C 1000 a Identify the amplitude of f b Identify the period o
Solution
10 . f(x)= 4sin(2(x-2)) + 12
= 4sin(2x-4)+12
This equation is of the form f(x)= Asin(Bx-C)+D
Amplitude ,A= 4
Period=2pi/B=2pi/2=pi
Phase shift=C/B= 4/2=2
6. tan(theta/2)=csc theta -cot theta
starting with the left side
tan(theta/2)= (1-costheta)/sin theta=1/sin theta - costheta/sin theta=csc theta-cot theta
b. (cos theta - sin theta)2=1-sin 2theta
starting with the left side
(cos theta - sin theta)2=cos2theta + sin2theta-2sin theta cos theta
and cos2theta + sin2theta=1 ,2sin thetacos theta=sin 2 theta
Therefore we get
1+ sin 2 theta
c. sin (theta/2)=sin theta/(sqrt2(1+cos theta))
using half angle identity
sin(theta/2)= sqrt((1-cos theta)/2)
Multiplying top and bottom by 1+cos theta inside the square root
sqrt((1-cos theta)(1+cos theta)/2(1+cos theta))= sqrt(sin2theta/2(1+cos theta))
= sin theta/sqrt(2(1+cos theta))
