Test Index

WAEC Mathematics 2010 Paper

© africaexams.com

Question : 27

Total: 49

x	0	2	4	6
y	1	2	3	4

The table is for the relation y = mx + c where m and c are constants. What is the equation of the line described in the tablet?

y = 2x
y = x + 1
y = x
y = $\;\frac{1}{2}x + 1$

Solution:

Concept:

The table values satisfy the linear relation

y = mx + c

; we determine the constants

m

and

c

using the given points.

Explanation:

Use the point

(0,1)

where

x=0

and

y=1

.

Substitute into

y=mx+c

:

1=m(0)+c

, so

c=1

.

Now use the point

(2,2)

with

c=1

:

2=m(2)+1

.

Simplify:

2-1=2m

, so

1=2m

.

Therefore,

m=\frac{1}{2}

.

Put

m=\frac{1}{2}

and

c=1

into

y=mx+c

.

Answer:

y=\frac{1}{2}x+1

© africaexams.com

Go to Question:

Prev Question

Next Question