WAEC Past Questions and Answers - Page 3863

19,311.

For what values of x is the expression \(\frac{3x-2}{4x^2+9x-9}\) undefined?

A.

\(\frac{-3}{4} \hspace{1mm}or \hspace{1mm}3\)

B.

\(\frac{-2}{3} \hspace{1mm}or \hspace{1mm}-3\)

C.

\(\frac{2}{3} \hspace{1mm}or \hspace{1mm}3\)

D.

\(\frac{3}{4} \hspace{1mm}or \hspace{1mm}-3\)

Correct answer is D

The equation \(\frac{3x - 2}{4x^2 + 9x - 9}\) is undefined when the denominator = 0.

\(4x^2 + 9x - 9 = 0\)

\(4x^2 + 12x - 3x - 9 = 0\)

\(4x(x + 3) - 3(x + 3) = 0\)

\((4x - 3)(x + 3) = 0\)

x = \(\frac{3}{4}\) or x = -3.

19,312.

In the diagram, SQ is a tangent to the circle at P, XP||YQ, ∠XPY = 56o and ∠PXY = 80o.Find angle PQY

A.

34o

B.

13.36o

C.

44o

D.

46o

Correct answer is A

< XYQ = 180° - (80° + 56°)

= 44°

< PYQ = 56° (alternate angles, XP||YQ)

< QPY = 90°

< PQY = 180° - (90° + 56°)

= 34°

19,313.

Which of the following is represented by the above sketch?

A.

y = x2 + x - 6

B.

y = x2 - x - 6

C.

y = x2 - x + 6

D.

y = x2 + x + 6

Correct answer is B

From the graph, the zeros of the equation exist at x = -2 and x = 3

\(\therefore\) (x + 2) = 0 and (x - 3) = 0

\(\implies (x + 2)(x - 3) = 0\)

\(x^2 - 3x + 2x - 6 = 0\)

\(x^2 - x - 6 = 0\) is the equation represented on the graph.

19,314.

If (-3, -4) is a point on the line y = mx + 2 find the value of m.

A.

-2

B.

\(\frac{7}{4}\)

C.

2

D.

\(\frac{8}{3}\)

Correct answer is C

If (-3, -4) is a point on the line then

-4 = -3m + 2

-4 - 2 = -3m

-6 = -3m

m = 2

19,315.

Find the nth term of the sequence 4, 10, 16 ,...

A.

2(3n- 1)

B.

2(2 + 3 n-1)

C.

2 n + 2

D.

2(3n+2)

Correct answer is A

\(T_{1} = 4; T_2 = 10; T_3 = 16\)

\(T_{2} - T_1 = T_3 - T_1 = 6\)

\(T_n = a + (n - 1) d\)

= \(4 + (n - 1) \times 6\)

= \(4 + 6n - 6\)

= \(6n - 2\)

= 2(3n - 1)