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Find the values of a for which the function f (x) = cos x - sin x + ax + b is decreasing.

Find the values of a for which the function f (x) = cos x - sin x + ax + b is decreasing.

Grade:12

1 Answers

Rinkoo Gupta
askIITians Faculty 80 Points
7 years ago
f’(x)<0
-sinx-cosx+a<0
a<sinx+cosx
sinx+cosx>a
sqrt2[1/sqrt2 .sinx+1/sqrt2.cosx]>a
sin(x+pi/4)>a/sqrt2
a/sqrt2<sin(x+pi/4)
moda<sqrt2. mod sin(x+pi/4)
moda,<sqrt2.1
moda<sqrt2
-sqrt2<a<sqrt2
Thanks & Regards
Rinkoo Gupta
AskIITians Faculty

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