Help me with my trig homework please?

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Help me with my trig homework please?

Simplyfy cos (pie\2 -x)

2007-01-06 10:06:08 · 4 answers · asked by christian8807 3 in Science & Mathematics ➔ Mathematics

4 answers

cos(a-b) = cos(a)cos(b) + sin(a)sin(b)
In this case a is pi/2 and b is x so,

cos(pi/2 - x) = cos(pi/2)cos(x) + sin(pi/2)sin(x)
= 0*cos(x) + 1*sin(x)
=sin(x)

2007-01-06 10:25:47 · answer #1 · answered by hunneebee22 4 · 0⤊ 0⤋

Use the angle addition formula for cosines.

cos(a - b) = (cos a)(cos b) + (sin a)(sin b)

2007-01-06 18:18:37 · answer #2 · answered by Northstar 7 · 0⤊ 0⤋

Do you mean cos((pi/2)-x) or cos(pi/(2-x))?

2007-01-06 18:08:56 · answer #3 · answered by Nick R 4 · 0⤊ 0⤋

pay attention in class or get a tutor. We won't give you the answer for your homework.

2007-01-06 18:07:34 · answer #4 · answered by itguru5354 1 · 0⤊ 2⤋