WISKUNDE
GRAAD 10
NOG OEFENINGE
  
Gradiënte van lyne : antwoorde.
  
MATHEMATICS
GRADE 10
MORE EXERCISES
  
Gradients of lines : answers.
  

Antwoord / Answer 1  

                            yB − yA
    1.1  m(AB) = ──────   
                            xB − xA
  
                            7 − 3
                      = ──────   
                            4 − 2
  
                            4
                      = ───       =  2
                            2
  
  
  
                            yL − yK
    1.3  m(KL) = ──────   
                            xL − xK
  
                            −2 − (−17)
                      = ─────────   
                            −4 − (−7)
  
                            15
                      = ───        =  5
                            3
  
  
  
                            yS − yR
    1.5  m(RS) = ──────   
                            xS − xR
  
                            6 − (−2)
                      = ─────────   
                            −1 − (−7)
  
                            8                 4
                      = ───        =  ──
                            6                 3
                            yD − yC
    1.2  m(CD) = ──────   
                            xD − xC
  
                            18 − 3
                      = ──────   
                            6 − 1
  
                            15
                      = ───       =  3
                            5
  
  
  
                            yQ − yP
    1.4  m(PQ) = ──────   
                            xQ − xP
  
                            −23 − (−7)
                      = ─────────   
                            3 − (−5)
  
                           −16
                      = ────        =  −2
                             8
  
  
  
                            yB − yA
    1.6  m(AB) = ──────   
                            xB − xA
  
                            −13 − (−8)
                      = ─────────   
                            3 − (−6)
  
                           −5                       5
                      = ────        =  −  ──
                             9                       9

Antwoord / Answer 2  

               yB − yA
    2.1    ──────   =  m(AB)
               xB − xA
  
                 10 − 4
              ──────    =  2
                  b − 5
  
                   2(b − 5)  =  10 − 4
  
                   2b − 10  =  6
  
                             b  =  8
  
  
  
               yL − yK
    2.3    ──────   =  m(KL)
               xL − xK
  
               −4 − 6
            ──────    =  − 1
                10 − k
  
             −1(10 − k)  =  −4 − 6
  
                  −10 + k  =  −10
  
                             k  =  0
  
  
  
  
               yS − yR
    2.5    ──────   =  m(RS)
               xS − xR
  
              −12 − r                              4
            ──────    =  − 0,8   =  − ──
              2 − (−8)                             5
  
            −5(−12 − r)  =  4(2 − (−8))
  
                   60 + 5r  =  40
  
                           5r  =  40 − 60
  
                             r  =  −4
  
  
               yD − yC
    2.2    ──────   =  m(AB)
               xD − xC
  
                 d − 12
              ──────  =  − 2
                  7 − 3
  
                   d − 12  =  −2(7 − 3)
  
                           d  =  −2 × 4  +  12
  
                           d  =  4
  
  
  
               yQ − yP
    2.4    ──────   =  m(PQ)
               xQ − xP
  
               −4 − p                        4
           ───────  =  0,8   =  ──
            −3 − (−8)                      5
  
              5(−4 − p)  =  4(−3 − (−8))
  
              −20 − 5p  =  4 × 5
  
                      −5p  =  20 + 20
  
                          p  =  −8
  
  
               yB − yA
    2.6    ──────   =  m(AB)
               xB − xA
  
               3 − 10                             1
           ───────  =  −0,5   =  − ──
              b − (−8)                            2
  
          −1(b − (−8))  =  2(3 − 10)
  
                   −b − 8  =  2 × (−7)
  
                         −b  =  −14 + 8
  
                           b  =  6
  
  

Antwoord / Answer 3  

        Punte A, B en C is saamlynig as m(AB)  =  m(AC)
  
  
        Points A, B and C are collinear if m(AB)  =  m(AC)
  
  

Antwoord / Answer 3.1  

                            yB − yA                                  yC − yA
           m(AB) = ──────       ;        m(AC) = ──────
                            xB − xA                                  xC − xA
  
                            12 − 2                                      22 − 2
                      = ───────                          = ───────
                            2 − (−3)                                   7 − (−3)
  
                           10                                            20
                      = ────                                 = ────
                            5                                             15
  
                      =  2                                         =  2
  
  
                m(AB) = m(AC)
  
  
                A, B en / and C  is saamlynig.    / are collinear.
  
    
Vraag / Question 3.1

  

Antwoord / Answer 3.2  

                            yE − yD                                 yF − yD
           m(DE) = ──────       ;        m(DF) = ──────
                            xE − xD                                  xF − xD
  
                            −2 − 8                                     −22 − 8
                      = ─────────                    = ─────────
                            −2 − (−7)                                 8 − (−7)
  
                           −10                                        −30
                      = ────                                 = ────
                              5                                           15
  
                      =  − 2                                     =  − 2
  
  
                m(DE) = m(DF)
  
  
                D, E en / and F  is saamlynig.    / are collinear.
  
    
Vraag / Question 3.2

  

Antwoord / Answer 3.3  

                            yH − yG                                 yI − yG
           m(GH) = ──────       ;        m(GI) = ──────
                            xH − xG                                 xI − xG
  
                           −3 − (−7)                                5 − (−7)
                      = ───────                         = ───────
                           −3 − (−5)                                1 − (−5)
  
                             4                                            12
                      = ────                                 = ────
                             2                                             6
  
                      =  2                                         =  2
  
  
                m(GH) = m(GI)
  
  
                G, H en / and I  is saamlynig.    / are collinear.
  
  
    
Vraag / Question 3.3

  

Antwoord / Answer 3.4  

                           0 yL − yK                                yM − yK
           m(KL) = ──────       ;        m(KM) = ──────
                            xL − xK                                  xM − xK
  
                            6 − (−9)                                 8 − (−9)
                      = ─────────                    = ─────────
                           −2 − (−7)                                5 − (−7)
  
                             15                                          17
                      = ────                                 = ────
                              5                                           12
  
                      =  3                                                     
  
  
                m(KL) ≠ m(KM)
  
  
                K, L en / and M  is nie saamlynig nie.    / 
                                              are not collinear.
  
    
Vraag / Question 3.4

  

Antwoord / Answer 3.5  

                            yQ − yP                                  yR − yP
           m(PQ) = ──────       ;        m(PR) = ──────
                            xQ − xP                                  xR − xP
  
                             2 − 7                                       −5 − 7
                      = ───────                          = ───────
                           1 − (−4)                                   5 − (−4)
  
                             −5                                         −12
                      = ────                                 = ────
                             5                                              9
  
                      =  −1                                                      
  
  
                m(PQ) ≠ m(PR)
  
  
                P, Q en / and R  is nie saamlynig nie.    / 
                                              are not collinear.
  
    
Vraag / Question 3.5

  

Antwoord / Answer 3.6  

                            yB − yA                                  yC − yA
           m(AB) = ──────       ;        m(AC) = ──────
                            xB − xA                                  xC − xA
  
                              10 − 16                                 −12 − 16
                      = ─────────                    = ─────────
                                4 − 1                                     15 − 1
  
                             −6                                        −28
                      = ────                                 = ────
                              3                                           14
  
                      =  − 2                                     =  − 2
  
  
                m(AB) = m(AC)
  
  
                A, B en / and C  is saamlynig.    / are collinear.
  
  
    
Vraag / Question 3.6

  

Antwoord / Answer 4  

        AB || CD as m(AB) = m(CD) en
  
        AB ⊥ CD  as  m(AB) × m(CD)  =  −1
  
  
        AB || CD if m(AB) = m(CD) en
  
        AB ⊥ CD  if  m(AB) × m(CD)  =  −1
  
  

Antwoord / Answer 4.1  

                            yB − yA
           m(AB) = ──────
                            xB − xA
  
                                 6 − 2
                       = ─────────
                             −4 − (−6)
  
                             4
                       = ───      =  2
                             2
  
  
              m(||)  =  m(AB)  =  2
  
  
              m(⊥) × m(AB)  =  − 1
  
                              2
              m(⊥) × ───  =  − 1
                              1
  
                                               1
                           m(⊥) =  − ───
                                               2
  
  
    
Vraag / Question 4.1

  

Antwoord / Answer 4.2  

                            yD − yC
           m(CD) = ──────
                            xD − xC
  
                             −10 − 8
                       = ───────
                             4 − (−2)
  
                            −18
                       = ────      =  − 3
                               6
  
  
              m(||)  =  m(CD)  =  − 3
  
  
              m(⊥) × m(CD)  =  − 1
  
                                   3
              m(⊥) ×  −  ───  =  − 1
                                   1
  
                                                 1
                                m(⊥) =  ───
                                                 3
  
  
    
Vraag / Question 4.2

  

Antwoord / Answer 4.3  

                            yF − yE
           m(EF) = ──────
                            xF − xE
  
                                 20 − 6
                       = ─────────
                             1 − (−3)
  
                             14              7
                       = ───      =  ───
                              4              2
  
  
                                               7
              m(||)  =  m(EF)  =  ───
                                              2
  
  
              m(⊥) × m(EF)  =  − 1
  
                                 7
                 m(⊥) × ───  =  − 1
                                 2
  
                                                  2
                              m(⊥) =  − ───
                                                  7
  
  
    
Vraag / Question 4.3

  

Antwoord / Answer 4.4  

                            yH − yG
           m(GH) = ──────
                            xH − xG
  
                              1 − 11
                       = ───────
                               9 − 3
  
                            −10                  5
                       = ────      =  − ───
                               6                   3
  
  
                                                   5
              m(||)  =  m(GH)  =  − ───
                                                   3
  
  
              m(⊥) × m(GH)  =  − 1
  
                                   5
              m(⊥) ×  −  ───  =  − 1
                                   3
  
                                                 3
                                m(⊥) =  ───
                                                 5
  
  
    
Vraag / Question 4.4