JAMB Mathematics Past Questions & Answers - Page 318

1,586.

A man walks 100 m due West from a point X to Y, he then walks 100 m due North to a point Z. Find the bearing of X from Z.

A.

195o

B.

135o

C.

225o

D.

045o

Correct answer is B

tan\(\theta\) = \(\frac{100}{100}\) = 1

\(\theta\) = tan-1(1) = 45o

The bearing of x from z is N45oE or 135o

1,587.

In a right angled triangle, if tan \(\theta\) = \(\frac{3}{4}\). What is cos\(\theta\) - sin\(\theta\)?

A.

\(\frac{2}{3}\)

B.

\(\frac{3}{5}\)

C.

\(\frac{1}{5}\)

D.

\(\frac{4}{5}\)

Correct answer is C

tan\(\theta\) = \(\frac{3}{4}\)

from Pythagoras tippet, the hypotenus is T

i.e. 3, 4, 5.

then sin \(\theta\) = \(\frac{3}{5}\) and cos\(\theta\) = \(\frac{4}{5}\)

cos\(\theta\) - sin\(\theta\)

\(\frac{4}{5}\) - \(\frac{3}{5}\) = \(\frac{1}{5}\)

1,588.

Find the equation of a line perpendicular to line 2y = 5x + 4 which passes through (4, 2).

A.

5y - 2x -18 = 0

B.

5y + 2x - 18 = 0

C.

5y - 2x + 18 = 0

D.

5y + 2x - 2 = 0

Correct answer is B

2y = 5x + 4 (4, 2)

y = \(\frac{5x}{2}\) + 4 comparing with

y = mx + e

m = \(\frac{5}{2}\)

Since they are perpendicular

m1m2 = -1

m2 = \(\frac{-1}{m_1}\) = -1

\(\frac{5}{2}\) = -1 x \(\frac{2}{5}\)

The equator of the line is thus

y = mn + c (4, 2)

2 = -\(\frac{2}{5}\)(4) + c

\(\frac{2}{1}\) + \(\frac{8}{5}\) = c

c = \(\frac{18}{5}\)


y = -\(\frac{2}{5}\)x + \(\frac{18}{5}\)

5y = -2x + 18

or 5y + 2x - 18 = 0

1,589.

The midpoint of P(x, y) and Q(8, 6) is (5, 8). Find x and y.

A.

(2, 10)

B.

(2, 8)

C.

(2, 12)

D.

(2, 6)

Correct answer is A

P(x, y) Q(8, 6)

midpoint = (5, 8)

x + 8 = 5

\(\frac{y + 6}{2}\) = 8

x + 8 = 10

x = 10 - 8 = 2

y + 6 = 16

y + 16 - 6 = 10

therefore, P(2, 10)

1,590.

The perpendicular bisector of a line XY is the locus of a point 

A.

whose distance from X is always twice its distance from Y

B.

whose distance from Y is always twice its distance from X.

C.

which moves on the line XY

D.

which is equidistant from the points X and Y

Correct answer is D

No explanation has been provided for this answer.