Question

find the least possible value of alpha for which

1)
sin (alpha-theta) =cos (alpha + theta)

2)
sin ( theta + 2*alpha) = cos (alpha - theta )

Answer 1

they look tricky, what have you tried so far ?

Answer 2

Hello @ganeshie8 , thanks for trying at least to answer.
well ..

I tried to draw both trigonmetric eqn ( cos x and sin x ) and assumed that theta to be always zero .. but im wondering if i shud refer to the trig ratios

Answer 3

@math&ing001

Answer 4

Well the least value for witch sin=cos is pi/4
If we put alpha+theta=alpha-theta => theta=0 & alpha=pi/4
I'm not sure about this though, maybe try something along the lines of
sin(A-B)=sin A cos B - cos A sin B
cos(A+B)=cos A cos B - sin A sin B
and see where it gets you. Sorry couldn't be much help.