The greatest value of f(x) = cos (xe(x) + 7x2 - 3x),x ∈ [-1, ∞ ) is :

Question

The greatest value of f(x) = cos (xe(x) + 7x2 - 3x),x ∈ [-1, ∞ ) is : (A) -1 (B) 1 (C) 0 (D) none of these

Tardigrade Admin · Accepted Answer

Given: f (x) = cos (xex + 7x2 - 3x), x ∈ [-1, ∞) we know that -1 le cos θ le 1 ∴ greatest value of cos θ is 1 Hence, greatest value of cos (x.ex + 7x2 - 3x) is 1.

Q. The greatest value of $f (x) = cos (x e^{(x)} + 7 x^{2} - 3 x), x \in [- 1, \infty)$ is :

-1

1

0

none of these

Given : $f (x) = cos (x e^{x} + 7 x^{2} - 3 x), x \in [- 1, \infty)$
we know that $- 1 \leq cos θ \leq 1$
$∴$ greatest value of cos $θ$ is 1
Hence, greatest value of $cos (x . e^{x} + 7 x^{2} - 3 x)$ is 1.

Q. The greatest value of f(x)=cos(xe(x)+7x2−3x),x∈[−1,∞) is :

-1

1

0

none of these

Given : f(x)=cos(xex+7x2−3x),x∈[−1,∞) we know that −1≤cosθ≤1 ∴ greatest value of cos θ is 1 Hence, greatest value of cos(x.ex+7x2−3x) is 1.

Q. The greatest value of $f (x) = cos (x e^{(x)} + 7 x^{2} - 3 x), x \in [- 1, \infty)$ is :

Given : $f (x) = cos (x e^{x} + 7 x^{2} - 3 x), x \in [- 1, \infty)$
we know that $- 1 \leq cos θ \leq 1$
$∴$ greatest value of cos $θ$ is 1
Hence, greatest value of $cos (x . e^{x} + 7 x^{2} - 3 x)$ is 1.