Logarithmic graphs and modelling Quiz

1. $y=5x^{3}$. A graph of $\lg y$ against $\lg x$ has gradient:

• A. $5$
• B. $3$
• C. $\lg5$
• D. $\lg3$

2. $y=2\times3^{x}$. A graph of $\lg y$ against $x$ has intercept:

• A. $\lg3$
• B. $2$
• C. $3$
• D. $\lg2$

3. A graph of $\lg y$ against $\lg x$ has gradient $1.5$ and intercept $1$. Find $a$ in $y=ax^n$.

• A. $1$
• B. $1.5$
• C. $10$
• D. $15$

4. A graph of $\lg y$ against $x$ has gradient $0.3$. Find $b$ to 3 s.f. in $y=kb^x$.

• A. $0.3$
• B. $1.35$
• C. $2.00$
• D. $3.00$

5. If $\lg y=0.5x+1$, find $y$ when $x=4$.

• A. $1000$
• B. $100$
• C. $3$
• D. $10^{4}\times0.5$