SOLUTION: proving compound angle formula
a) tan(x+45)-tan(x-45)= 4tanx/1-tan^2x
b) sin(x-30)-cos(x+60)=square root 3sinx-cos x
plz help me am stuck thx lots
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-> SOLUTION: proving compound angle formula
a) tan(x+45)-tan(x-45)= 4tanx/1-tan^2x
b) sin(x-30)-cos(x+60)=square root 3sinx-cos x
plz help me am stuck thx lots
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Question 1119399: proving compound angle formula
a) tan(x+45)-tan(x-45)= 4tanx/1-tan^2x
b) sin(x-30)-cos(x+60)=square root 3sinx-cos x
plz help me am stuck thx lots Found 2 solutions by Edwin McCravy, AnlytcPhil:Answer by Edwin McCravy(20060) (Show Source):
That's not true, for if you substitute x = 100°,
you get 45.71229319 = -3.585054968, so
you must have copied it wrong.
But the second one is true:
Work with left side only:
Edwin
I have discovered what your copying error in the first
one must have been. The sign between the terms in the
numerator of the left side should have been +, not -.
Work with left side only:
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Work with left side only:
Edwin (aka AnlytcPhil)
