Does anyone know how to solve this?

Step-by-step explanation:

This almost looks like the left hand side of the following identity:

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Here are similar identities in the same category as the above:

Things to notice: 90-76=14. and 90-59=31.

This means we will possibly want to use the following co-function identities:

So let's begin:

Applying the co-function identities:

Applying one of the difference identities above with cosine:

45 is a special angle so is something you find off most unit circles in any trigonometry class.