A.Maths answers on St. Lines

Straight Lines

Section A

1. P is (5/2, 0)

2. R is (2, -7),  mid-pt of PR is (5/2, 0), mid-pt of QR is (0,-1)

3. x = 6, y = -3

4. B is (3, -2), C is (1,3)

5. a) 3 + (square root of 3)

      b) (square root of 6) + (square root of 2)

6. (-3, 0) or (19/5, 0)

7. a) -2

    b) 2x+y-11=0

    c) (8+(square root of 5))/5

8. a) b=(2a+4)/3

    b) (19,14) or (7,6)

9. a) P= ( (-2+k)/(1+k), (2+7k)/(1+k) )

    b) 2:7

10.a) ( (k²-1)/(k²+1), (-2k)/(k²+1)

    b) (x²)+(y²)=1

11.a) mx-y+1-2m=0

    b) m = 7 or -1

Section B

1. a) Slope AB=4/3, slope AD=-7

    b) Slope AC=-3/4

    c) 10+5*(square root of 2)

2. a) C=( 4/(1+r), 8/(1+r) )

        D=( 10r/(1+r), 4r/(1+r) )

    b) Area of ABC= 32- (32/ (1+r))

        Area of BCD= (32/ (1-r) )- (32r/ (1+r)² )

    c) r=2