If f'(x)=0 in an interval then how can f(x) be?

A. constant

Step 1: Identify the concept: this is derivative and constant function. Step 2: If derivative is zero in an interval the function is not changing and can be constant. Step 3: Remember zero derivative means no change.

Step 1: concept पहचानें: यह derivative and constant function है। Step 2: किसी interval में derivative zero होने का अर्थ है function change नहीं कर रहा और constant हो सकता है। Step 3: Zero derivative means no change याद रखें।