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Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Sadie computes the perimeter of a rectangle by adding the length, l, and width, w, and doubling this sum. eric computes the perimeter of a rectangle by doubling the length, l, doubling the width, w, and adding the doubled amounts. write an equation for sadie’s way of calculating the

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12