Question

Write the equation of line, in slope-intercept form, that is perpendicular to y = \frac{1}{4}x y = 1 4 x and passes through the point (2, -5). Your answer must be in y = mx + b form or will be marked wrong.

Answer 1

Y = 1/4x....slope here is 1/4. A perpendicular line will have a negative reciprocal slope. To find the negative reciprocal, " flip " the number and change the sign. So the negative reciprocal for our perpendicular line is -4.

y = mx + b
slope(m) = -4
(2,-5)...x = 2 and y = -5
now we sub and find b, the y int
-5 = -4(2) + b
-5 = -8 + b
-5 + 8 = b
3 = b

so ur perpendicular equation is : y = -4x + 3