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Hello,
I am going through some home work set to be completed before school starts and I am having trouble with a few questions.
Simplify sin(a+b)cos(a-b)-cos(a+b)sin(a-b)
Prove Identities
i. (sintheta)^2 = 1/2 -1/2cos2theta
ii. (costheta)^2 = 1/2 + 1/2cos2theta
Using what is learned from above. find period of:
i. y=sint^2
ii. y= 1+(cos2t)^2
iii. y= 1-(4sin3t)^2
Relevant equations
cos(a+b) = cosacosb-sinasinb
cos(a-b) = cosacosb+sinasinb
sin(a+b) = sinacosb+cosasinb
sin(a-b) = sinacosb+cosasinb
sin2a=2sinacosa
cos2a = cos^2A-sin^2A
= 2cos^2A - 1
= 1-2sin^2A
cost^2 + sint^2 = 1
The attempt at a solution
I have tried numeros times to expand and simplify the equations but I never get the correct answer.
Any Help is appreciated
thanks
I am going through some home work set to be completed before school starts and I am having trouble with a few questions.
Simplify sin(a+b)cos(a-b)-cos(a+b)sin(a-b)
Prove Identities
i. (sintheta)^2 = 1/2 -1/2cos2theta
ii. (costheta)^2 = 1/2 + 1/2cos2theta
Using what is learned from above. find period of:
i. y=sint^2
ii. y= 1+(cos2t)^2
iii. y= 1-(4sin3t)^2
Relevant equations
cos(a+b) = cosacosb-sinasinb
cos(a-b) = cosacosb+sinasinb
sin(a+b) = sinacosb+cosasinb
sin(a-b) = sinacosb+cosasinb
sin2a=2sinacosa
cos2a = cos^2A-sin^2A
= 2cos^2A - 1
= 1-2sin^2A
cost^2 + sint^2 = 1
The attempt at a solution
I have tried numeros times to expand and simplify the equations but I never get the correct answer.
Any Help is appreciated
thanks