Starter 15 November 2021

What are the 2 things needed to create equation of a straight line

• gradient

• y-intercept

• the y-axis

• x-axis

Which of the following is the formula for gradient?

• A

• B

• C

• D

Answer explanation

It is okay if you insert y1 first.

But you need to do the same for the denominator.

The  gradient  of  the  line  y  =  4x  +  2

• 4

• 2

Calculate the equation of the straight line

• y = 2x - 1

• y = 2x + 1

• y = -2x - 1

• y = 0.5x -1

Answer explanation

1) Calculate the gradient, m, using the formula

2) Substitute the coordinates

3) Identify c: the points where it cuts the y-axis.

4) Substitute the found m & c into y=mx+c

Calculate the equation of the straight line

• y = - x - 7

• y = -x + 7

• y = - 2x + 7

• y = 2x + 7

Answer explanation

In step 3:

1) Pick one known coordinates

2) Pick the coordinate where it cut the y-axis : (0, c)

3) Substitute into the eqn

4) Use the same gradient