Question

If `sin x + cos x = 1.2`, then `sin x - cos x` can be written in the form `+-sqrtA`. What is `A`?

Answer 1

`(sinx-cosx)^2+(sinx+cosx)^2=2(sin^2x+cos^2x)`

`=>(sinx-cosx)^2+(1.2)^2=2xx1`

`=>(sinx-cosx)^2=2-1.44=0.56`

`=>(sinx-cosx)=pmsqrt0.56`

So `A= 0.56`