2.4 SPM Practice (Short Questions)


2.4 SPM Practice (Short Questions)

Question 1:
Which of the following graphs represent y = –x2 – x + 2?



Solution:
1.      The coefficient of x2 < 0, its shape is .
2.      Find the x-intercepts by substituting y = 0 into the function.
y = –x2x + 2
when y = 0
0 = (–x + 1) (x + 2)
x = 1, –2

The answer is A.


Question 2:
Which of the following graphs represent 3y = 18 + 2x?





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 /.

3y = 18 + 2x
On the y-axis, x = 0.
3y = 18
y = 6

On the x-axis, y = 0.
0 = 18 + 2x
2x = –18
x = –9

The answer is B.