5.3 Differentiating polynomials Quiz

1. Differentiate $f(x)=2x^{4}-3x^{2}+x-9$.

• A. $8x^{3}-6x+1$
• B. $8x^{3}-6x$
• C. $8x^{3}-6x+1-9$
• D. $2x^{3}-3x+1$

2. Differentiate $y=\frac{5}{x^{3}}$.

• A. $\frac{15}{x^{2}}$
• B. $-\frac{15}{x^{2}}$
• C. $-\frac{15}{x^{4}}$
• D. $\frac{5}{3x^{2}}$

3. Find the gradient of $y=x^{2}-6x$ at $x=1$.

• A. $-5$
• B. $-4$
• C. $2$
• D. $-6$

4. Differentiate $y=x(x^{2}+1)$.

• A. $2x$
• B. $3x^{2}+1$
• C. $x^{2}+1$
• D. $3x^{2}$

5. At which $x$ does $y=x^{2}+4x$ have gradient 10?

• A. $x=3$
• B. $x=6$
• C. $x=2.5$
• D. $x=21$