Answer:
Step-by-step explanation:
the answer is correct so good job ok
Use a sum or difference identity to find the exact value of cos without a calculator. to work this, we look at the 75° to see if its the sum or difference of any angles from our reference triangles.now plug in values from your reference triangles.
Example:
This suggests two solutions,
and
.
However, upon plugging these solutions back into the equation, you get
which checks out, but
does not because
is defined only for
(assuming you're looking for real solutions only). So, we call
an extraneous solution, and the complete solution set (over the real numbers) is
.
Answer:
i believe it is B, havent used that skill in a bit !!