Find the derivative of the function f(x) = x² + 3x
Problem
The function f(x) = x² + 3x is given. Find its derivative f′(x).
Answer
f′(x) = 2x + 3
Step-by-step solution
Step 1. Recall the rule
The derivative of a sum equals the sum of the derivatives: . So we differentiate each term separately.
Step 2. Derivative of the first term
For a power function . Therefore .
2 more steps — unlocked after you sign in:
- Step 3. Derivative of the second term
- Step 4. Assemble the answer
Free · takes a minute
Common mistakes
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Forgetting that the derivative of a constant is zero (there is no constant here, but in f(x)=x²+3x+5 the term 5 disappears).
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Writing instead of — losing the factor from the exponent.