Question

The derivative of $\sin x$ is:

• A. $\cos x$
• B. $-\cos x$
• C. $-\sin x$
• D. $\tan x$

Hint:

A helpful mnemonic: Derivatives of "Co-" functions (Cosine, Cotangent, Cosecant) always start with a \textbf{negative} sign. Since Sine is not a "Co-" function, its derivative is positive.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Standard trigonometric derivatives are fundamental formulas in calculus. The derivative represents the rate of change or the slope of the tangent to the curve at any point.
Step 2: Detailed Explanation:
By using the first principle of derivatives or standard limits: $$\frac{d}{dx}(\sin x) = \cos x$$
Step 3: Final Answer:
The correct option is (a).