**2.4 SPM Practice (Short Questions)**

**Question 1:**

Which of the following graphs represent

*y*= –*x*^{2}–*x*+ 2?

*Solution:*
1. The
coefficient of

*x*^{2 }< 0, its shape is ∩.
2. Find
the

*x*-intercepts by substituting*y*= 0 into the function.*y*= –

*x*

^{2}–

*x*+ 2

when

*y*= 0
0
= (–

*x*+ 1) (*x*+ 2)*x*= 1, –2

The answer is

**.***A***Question 2:**

Which of the following graphs represent 3

*y*= 18 + 2*x*?

*Solution:*
1. The
highest power of

*x*= 1, it is a linear graph, i.e. a straight line.
2. The
coefficient of

*x*> 0, the straight line is**/**.
3

*y*= 18 + 2*x*
On the

*y*-axis,*x*= 0.
3

*y*= 18

*y***= 6**

On the

*x*-axis,*y*= 0.
0 = 18 + 2

*x*
2

*x*= –18

*x***= –9**

The answer is

**.***B*