Given that sin 60° ≈ 0.866, write the
cosine of a complementary angle

Step-by-step explanation:

Complement to 60° = 30°

cos(30°) = sin(60°) = 0.866

0.866.

Step-by-step explanation:

We use the identity

sin x = cos (90-x)

So the cosine of the complementary angle is also 0.866.

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)