quick trig qu (1 Viewer)

[sikeveo]

Its late, I'm not sure how i stuffed this one. I didn't get a 9 in the second part. Could someone do the whole question? Cos i think i might have screwed part 1 which screwed part 2

 

[Templar]

Assuming theta is in radians (otherwise replace theta with theta/180)

a) theta*x+theta*4x+2*3x=240
theta=(240-5x)/5x

b) Area=theta/2 * (16x^2-x^2)
=(240-5x)15x/10x
=9x(40-x)

c) Max area when A'=0
A'=360-18x
x=20cm