Consider a<span> right triangle with </span><span>hypotenuse of 1.
sin x means to divide the side in front of the angle by </span>hypotenuse<span>
cos x means to divide the side beside the angle by hypotenuse
we know that a^2+b^2=c^2 now divide two sides by c^2

c is 1 also a/c means sinx and b/c is cos x so
sin^2(x)+cos^2(x)=1
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Answer:

Step-by-step explanation:
We want to simplify;

We expand the bracket to obtain;

We now group the like terms to obtain;

We now simplify to get;

The correct answer is C

There is one solution to this system of equations. The answer is B.