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Question
The values of a for which the function f(x) = sinx – ax + b increases on R are ______.
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Solution
The values of a for which the function f(x) = sinx – ax + b increases on R are `(-oo, -1)`.
Explanation:
We have f(x) = sin x – ax + b
⇒ f'(x) = cos x – a
For increasing the function f'(x) > 0
∴ cos x – a > 0
Since `cos x ∈ [-1, 1]`
∴ a < –1
⇒ `"a" ∈ (-oo, -1)`
Hence, the value of a is `"a" ∈ (-oo, -1)`.
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