Question #d5791

1 Answer
Apr 5, 2017

Y=-sqrt2sin(x+pi/4), or

Y=sqrt2sin(x+3pi/4).

Explanation:

Y=-sinx-cosx=-(sinx+cosx).

:. Y=-sqrt2(1/sqrt2sinx+1/sqrt2cosx)

=-sqrt2{sinxcos(pi/4)+cosxsin(pi/4)}

:. Y=-sqrt2sin(x+pi/4).

If, A is reqd. to be +ve, then, we can rewrite Y as,

Y=sqrt2{(-1/sqrt2)sinx+(-1/sqrt2)cosx}, so that,

Y=sqrt2{sinxcos(3pi/4)+cosxsin(3pi/4)}, or,

Y=sqrt2sin(x+3pi/4).

Enjoy Maths.!