Choose the equation of the line passing through the point (-2, 4) and perpendicular to
y = -1/2x + 4.

A. y = 2x + 8

B. y = 2x

C. y = -2x - 8

D. y = -2x

Question

Choose the equation of the line passing through the point (-2, 4) and perpendicular to 
y = -1/2x + 4. 

A. y = 2x + 8 

B. y = 2x 

C. y = -2x - 8 

D. y = -2x

anonymous · Answer

when a line is perpendicular to another, their product is -1.
To find the gradient, divide -1 by -1/2 and you get 2.
The equation is now y = 2x + c
To find c, substitute the coordinates into the equation.
4 = -4 + c
c = 8
Therefore, the equation is y = 2x + 8
so the answer is A