WAEC Past Questions and Answers - Page 1037

5,181.

Simplify \(\frac{1}{3}\) log8 + \(\frac{1}{3}\) log 64 - 2 log6

A.

log \(\frac{2}{7}\)

B.

log 2

C.

log \(\frac{2}{9}\)

D.

log 9

Correct answer is C

\(\frac{1}{3}\) log8 + \(\frac{1}{3}\) log 64 - 2 log6

= log 2 + log 4 - log 36

= log \(\frac{8}{36}\)

= log \(\frac{2}{9}\)

5,182.

Given that M = \(\begin{pmatrix} 3 & 2 \\ -1 & 4 \end{pmatrix}\) and N = \(\begin{pmatrix} 5 & 6 \\ -2 & -3 \end{pmatrix}\), calculate (3M - 2N)

A.

\(\begin{pmatrix} 1 & 6 \\ 1 & 18 \end{pmatrix}\)

B.

\(\begin{pmatrix} -1 & -6 \\ 1 & 18 \end{pmatrix}\)

C.

\(\begin{pmatrix} 1 & 6 \\ -1 & -18 \end{pmatrix}\)

D.

\(\begin{pmatrix} -1 & -6 \\ -1 & -18 \end{pmatrix}\)

Correct answer is B

3M = 3 \(\begin{pmatrix} 3 & 2 \\ -1 & 4 \end{pmatrix}\)

 = \(\begin{pmatrix} 9 & 6 \\ -3 & 12 \end{pmatrix}\)

2N = 2 \(\begin{pmatrix} 5 & 6 \\ -2 & -3 \end{pmatrix}\) 

= \(\begin{pmatrix} 10 & 12 \\ -4 & -6 \end{pmatrix}\)

(3M - 2N) = \(\begin{pmatrix} 9 & 6 \\ -3 & 12 \end{pmatrix}\) - \(\begin{pmatrix} 10 & 12 \\ -4 & -6 \end{pmatrix}\)

5,183.

For what range of values of x is x\(^2\) - 2x - 3 ≤ 0

A.

{x: -1 ≤ x ≤ 3}

B.

{x: -3 ≤ x ≤ 1}

C.

{x: -3 ≤ x ≤ -1}

D.

{x: 1 ≤ x ≤ 3}

Correct answer is A

Let  x\(^2\) - 2x - 3 = 0;

(x+1)(x-3) = 0

 The zeros of the function are x = -1 and 3

The solution set is { x: -1 ≤ x ≤ 3}

5,184.

Simplify ( \(\frac{1}{2 - √3}\) + \(\frac{2}{2 + √3}\) )\(^{-1}\)

A.

\(\frac{-1}{33}\)(6 + √3)

B.

\(\frac{-1}{33}\)(6 - √3)

C.

\(\frac{1}{33}\)(6 + √3)

D.

\(\frac{1}{33}\)(6 - √3)

Correct answer is C

( \(\frac{1}{2 - √3}\) + \(\frac{2}{2 + √3}\) )\(^{-1}\)

= \(\frac{2 + √3 + 2(2 - √3)}{(2 - √3)(2 + √3)}\)

= 2 + √3 + 4 - 2√3 

= (6 - √3)\(^{-1}\)

= \(\frac{1}{6 - √3}\)

= \(\frac{6 + √3}{6 - √3  *  6 + √3}\)

= \(\frac{6 + √3}{33}\)

5,185.

Consider the statements:

x: Birds fly

y:  The sky is blue

Which of the following statements can be represented as x \(\to\) y?

A.

When birds fly, the sky is blue

B.

Birds fly if and only if the sky is blue?

C.

Either the bird is flying or the sky is blue.

D.

When the sky is blue, the bird flies.

Correct answer is B

No explanation has been provided for this answer.