Question

write the equation for a line that passes through (-2,3) and is perpendicular to the line 3x+4y=-7. Write in point-slope form.

Answer 1

3x+4y=-7
4y=-3x-7
divide by 4 all through
y=-3/4x-7/4
gradient of this equation is -3/4
(-2,3)
perpendicular is normally equal to -1 when you multiply both the gradients of the two
that is; -3/4 * x = -1
x=4/3

this tends to be the gradient for the second equation

to find the equation for (-2,3) and we know the gradient is 4/3
y=mx+c
y=4/3x + c
(-2,3) is represnted by (x,y)
find change in y / change in x
y+3/x+2 = 4/3
3(y+3)=4(x+2)
3y+9=4x+8
3y=4x+8-9
3y=4x-1

Answer 2

3y-4x=-1

Answer 3

-4x+3y=-1