Question

If a cos theta + b sin theta= m and a sin thetha -b cos theta =n prove thata square + b square = m square

Answer 1

Answer:

acos@+bsin@=m is first equation and asin@_bcos@=n is second equation squaring both equation and add both, we get a²cos²@+b²sin²@+2abcos@sin@+a²sin²@+b²cos²@-2abcos@sin@=m²+n² a²(cos²@+sin²@)+b²(cos²@+sin²@)=m²+n² so a²+b²= m²+n²