Fill in the blank. If necessary, use the slash mark ( / ) for a fraction bar.

If sin theta = 3/5, then cos theta = _____.

Question

Fill in the blank. If necessary, use the slash mark ( / ) for a fraction bar.

If sin theta = 3/5, then cos theta = _____.

Hero · Answer

@birginiaxv, any ideas on how to start this?

Mercury · Answer

old question but will answer so this can be closed
sin(theta) = opposite/hypotenuse, so we can sketch a right triangle with the quantities from the problem
|dw:1553039388253:dw|

Mercury · Answer

cos(theta) = adjacent/hypotenuse by definition
so you just need to solve for the adjacent side using the Pythagorean theorem, then plug into cos(theta) = adjacent/hypotenuse