<h3>
Answer: cos(76)</h3>
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Explanation:
The original expression is of the pattern cos cos + sin sin. This pattern matches the second identity in the hint. Specifically, we'll say the following:
cos(A - B) = cos(A)cos(B) + sin(A)sin(B)
cos(A)cos(B) + sin(A)sin(B) = cos(A - B)
cos(94)cos(18) + sin(94)sin(18) = cos(94 - 18)
cos(94)cos(18) + sin(94)sin(18) = cos(76)
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We can verify this by use of a calculator. Make sure your calculator is in degree mode.
- cos(94)cos(18) + sin(94)sin(18) = 0.24192
- cos(76) = 0.24192
Both expressions give the same decimal approximation, so this helps confirm the two expressions are equal. You could also use the idea that if x = y, then x-y = 0. Through this method, you'll subtract the left and right hand sides and you should get (very close to) zero.
So, this is how we do it O w O<span><span>x = <span>−1</span></span>;<span>y = <span><span>3x</span>+1</span></span></span>Step: Solve <span>x = <span>−1 </span></span>for x:Step: Substitute <span>−1 </span>for x in <span><span>y = <span><span>3x</span>+1</span></span>:</span><span>y = <span><span>3x</span>+1</span></span><span>y = <span><span><span>(3)</span><span>(<span>−1</span>)</span></span>+1</span></span><span>y = <span>−2</span></span>(Simplify both sides of the equation)Answer:<span><span>x=<span>−<span><span>1<span> and </span></span>y</span></span></span>=<span>−<span>2
Hope I helped! :3</span></span></span>
