Differentiate sin x – x cos x
-
A.
x cos x -
B.
x sin x -
C.
-x cos x -
D.
-x sin x
Correct Answer: Option B
Explanation
sin x – x cos x
dy/dx = cos x – [1.cos x + x -sin x]
= co x – [cos x – x sin x]
= cos x – cos x + x sin x
= x sin x
sin x – x cos x
dy/dx = cos x – [1.cos x + x -sin x]
= co x – [cos x – x sin x]
= cos x – cos x + x sin x
= x sin x