programmerBlack
New member
 Joined
 Aug 15, 2019
 Messages
 2
Hello,
I'm working on a problem (nothomework), that requires me to find the exact value of tan(15 degrees) using angle addition or subtraction identities. I have found the answer to be sqrt(3)  3 / sqrt(3) + 3. I found this answer through trial and error. The first one I tried was was using tan (45  30), which yielded 1 (wrong) on Khan Academy. The second one I tried was tan(60  45), correct on Khan Academy.
My main question is this: How do I properly choose the angles so that my answer is correct the first time? Attached is a sample of my work. Thank you in advance.
I'm working on a problem (nothomework), that requires me to find the exact value of tan(15 degrees) using angle addition or subtraction identities. I have found the answer to be sqrt(3)  3 / sqrt(3) + 3. I found this answer through trial and error. The first one I tried was was using tan (45  30), which yielded 1 (wrong) on Khan Academy. The second one I tried was tan(60  45), correct on Khan Academy.
My main question is this: How do I properly choose the angles so that my answer is correct the first time? Attached is a sample of my work. Thank you in advance.
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