Quadratic functions and graphs Quiz

1. What is the minimum value of $x^2+4x+9$?

• A. $9$
• B. $5$
• C. $-5$
• D. $13$

2. The graph of $y=x^2+6x+k$ touches the $x$-axis. Find $k$.

• A. $3$
• B. $6$
• C. $9$
• D. $36$

3. The equation $2x^2-3x+m=0$ has two distinct real roots. Which condition on $m$ is correct?

• A. $m<\frac98$
• B. $m>\frac98$
• C. $m<\frac94$
• D. $m>\frac94$

4. A quadratic has a maximum value of 7 at $x=1$. Which could be its equation?

• A. $y=(x-1)^2+7$
• B. $y=-(x+1)^2+7$
• C. $y=-(x-1)^2-7$
• D. $y=7-(x-1)^2$

5. The graph of $y=x^2-4x+c$ does not cross the $x$-axis. Which is true?

• A. $c<4$
• B. $c=4$
• C. $c>4$
• D. $c<-4$