Mathematics questions and answers

Mathematics Questions and Answers

How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.

91.

The locus of a point equidistant from two intersecting lines is

A.

where the sum of the distances of two focal points is fixed

B.

the collection of points that are equally distant from a fixed point and a line

C.

the perpendicular bisector of the lines

D.

pair of bisectors of the angles between the two lines

Correct answer is C

The locus of a point equidistant from two intersecting lines is pair of bisectors of the angles between the two lines.

92.

What is the general term of the sequence 3, 8, 13, 18, ...?

A.

5n - 2

B.

5n + 2

C.

5

D.

5n

Correct answer is A

Given the sequence 3, 8, 13, 18, ... which is an arithmetic sequence

a = 3

d = T\(_2\) - T\(_1\) = 8 - 3 = 5

The general term of an A.P is:

T\(_n\) = a + (n - 1)d

⇒ T\(_n\) = 3 + (n - 1)5

= T\(_n\) = 3 + 5n - 5

∴ T\(_n\) = 5n - 2

93.

Solve the following quadratic inequality: \(x^2 - x\) - 4 ≤ 2

A.

\(-3 < x < 2\)

B.

\(-2 ≤ x ≤ 3\)

C.

\(x ≤ -2, x ≤ 3\)

D.

\(-2 < x < 3\)

Correct answer is B

\(x^2 - x - 4 ≤ 2\)
Subtract two from both sides to rewrite it in the quadratic standard form:
= \(x^2 - x - 4 - 2 ≤ 2 - 2\)
= \(x^2 - x - 6 ≤ 0\)
Now set it = 0 and factor and solve like normal.
= \(x^2 - x\) - 6=0
= \((x - 3)(x + 2)\)=0
\(x\) + 2 = 0 or \(x\) - 3 = 0
\(x\) = -2 or \(x\) = 3
So the two zeros are -2 and 3, and will mark the boundaries of our answer interval. To find out if the interval is between -2 and 3, or on either side, we simply take a test point between -2 and 3 (for instance, \(x\) = 0) and evaluate the original inequality.
= \(x2 - x - 4 ≤ 2\)
= \((0)^2 - (0) - 4 ≤ 2\)
= \(0 - 0 - 4 ≤ 2\)
\(−4 ≤ 2\)
Since the above is a true statement, we know that the solution interval is between -2 and 3, the same region where we picked our test point. Since the original inequality was less than or equal, we include the endpoints.
∴ \(-2 ≤ x ≤ 3.\)

94.

Let a binary operation '*' be defined on a set A. The operation will be commutative if

A.

a*b = b*a

B.

(a*b)*c = a*(b*c)

C.

(b ο c)*a = (b*a) ο (c*a)

D.

None of the above

Correct answer is A

A binary operation '*' defined on a set A is said to be commutative only if a*b=b*a, ∀a, b∈A. If (a*b)*c=a*(b*c), then the operation is said to associative ∀ a, b∈ A. If (b ο c)*a=(b*a) ο (c*a), then the operation is said to be distributive ∀ a, b, c ∈ A.

95.

If \(-2x^3 + 6x^2 + 17x\) - 21 is divided by \((x + 1)\), then the remainder is

A.

32

B.

30

C.

-30

D.

-32

Correct answer is C

Let \(p(x) = -2x^3 + 6x^2 + 17x - 21\)

Using the remainder theorem

Let \(x + 1 = 0\)

∴ \(x = -1\)

Since, \((x + 1)\) divides \(p(x)\), then, remainder will be p(-1)

⇒ p(-1) = -2(-1)\(^3 + 6(-1)^2\) + 17(-1) - 21

∴ p(-1) = -30