A rain gutter is to be constructed of aluminum sheets 12 inches wide. After marking off a length of 4 inches from each edge, this length is bent up at an angle Θ. The area A of the opening may be expressed as the function: A(Θ) = 16 sin Θ • (cos Θ + 1). If Θ = 90°, what is the area of the opening?

Question

anonymous · Answer

@ParthKohli

anonymous · Answer

@ganeshie8 @mathmale

anonymous · Answer

just sub. by theta=90 in the area equation

anonymous · Answer

I have tried that. It gave me -14.22 which is not even close to one of the options.

anonymous · Answer

A. 21.8 in2

B.16.0 in2

C. 7.9 in2

D. 1.0 in2

anonymous · Answer

i got 16 in^2

anonymous · Answer

How?
I did 16sin 90 = 14.3 and cos90 +1 = -.99 and multiplied the two resulting in -14.22.

anonymous · Answer

16sin90=16   because sin90=1
cos90+1=1    because cos90=0