Sin(x)^2 = cos(x/2)^2

First of all, you can use

and the equation becomes

Now, from the known identity

we can half all the angles and we get

So, the equation has become

So, everything comes down to solve

The associated equation

has roots

So, we want one of the following

Solve for the associated angles and you're done

the ratio of grapes to blueberries she should use is 12: 3

step-by-step explanation:

if mandie is making 15 cups of fruit salad, the ratio of grapes to blueberries she should use is 12: 3.