A company sells widgets. The amount of profit, y, made by the company, is related to the selling price of each widget, x, by the given equation. Using this equation, find out
what price the widgets should be sold for, to the nearest cent, for the company to
make the maximum profit.
y = -x2 + 83x – 609

2, 3, 4 and 7  are correc.t

Step-by-step explanation:

sec^2 x = 1 + tan^2x

so sec^2 x - 1 = tan^2 x

So the second choice is correct.

sec^2 x - cos^2x - sin^2x

= sec^2 x - (cos^2x + sin^2 x()

= sec^2 x - 1

The third is correct.

sec^2x / csc^2x =  1 /  cos^2x / 1 / sin^2x

= sin^2x / cos^2x

= tan^2x

= 1 - sec^2 x

So the fourth choice is correct.

1 - cos^2x / cos^2 x

=  sin^2x / soc^2x

= tan^2x

= 1 - sec^2x

The seventh choice is correct.