If $$f(x) = \sin x + \cos x$$​, then the maximum value of f(x) is:

Correct option is C

Given:
​$$f(x) = \sin x + \cos x$$​​
Formula used:
​$$a \sin x + b \cos x \le \sqrt{a^{2} + b^{2}}$$​​
Solution:
Here a = 1 and b = 1
Maximum value of $$f(x) = \sqrt{1^{2} + 1^{2}}$$​​
​$$= \sqrt{2}$$​​
The correct answer is (c) $$\sqrt{2}.$$​​