Solve cos(x/2-15°) = sin15°?

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Solve cos(x/2-15°) = sin15°?

2007-04-15 08:42:40 · 4 answers · asked by bing9200 1 in Science & Mathematics ➔ Mathematics

4 answers

The answer is π or 180 degrees because
cos(90-15) = cos(75) = sin 15.

2007-04-15 08:53:43 · answer #1 · answered by steiner1745 7 · 0⤊ 0⤋

Taking x =90 d d means degrees
L.H.S.
cos (90d - 15d)
= cos90dcos15 + sin90d sin15
By formula:
cos(A-B)=cos A cos B + sin A sin B
= (0)(0.9659) + (1)(0.2588)
=0 + 0.2588
= 0.2588

R.H.S.
sin(15d) where d means degrees
=0.2588
Hence, L.H.S. = R.H.S.
Thus proved

2007-04-15 09:10:09 · answer #2 · answered by blossom 2 · 0⤊ 0⤋

cos(x/2)-cos15=sin15

cosx/2=sin15+cos15

covert to decimals

2007-04-15 08:46:29 · answer #3 · answered by Jessica B 3 · 0⤊ 1⤋

x equals 720

2007-04-15 08:50:42 · answer #4 · answered by coolrider 2 · 0⤊ 0⤋