One of the JAMB subjects that candidates are a little bit afraid of is Mathematics. The primary reason is that JAMB mathematics has some basic further mathematics in the question. And if you are not so sound in it, you are already at a disadvantage.
However, there are some hidden facts that you need to understand in JAMB mathematics that will enable you to score high in it. For this reason, I have decided to shed some light on hidden facts in JAMB mathematics.
Read: 5 steps to get a good mark in maths
What to Know
1. Learn differentiation, integration, matrix, permutation & combination, and polynomials at the foundation level
The topics I just mentioned are simple because they have already made formulas that will enable you to solve any question on them. Don’t let anyone scare you since JAMB will only bring out simple questions from these topics.
2. Make sure you master logarithms & indices, surd, circle geometry, probability, set, number base, mean, median and mode well
These are essential topics you need to work more on to increase your chance of scoring high in JAMB mathematics. They are simple and easy to solve if can practice them as many times as possible
3. Work on your speed
JAMB mathematics is different from other subjects being that it can waste your time if you don’t know how to manage your time. Most times I do advise candidates who aren’t fantastic in mathematics to make it the last subject to answer. However, you can find some JAMB online CBT on math that you can practice with before the exam day. Using this approach will help increase your speed.
4. Anybody can score high in it
Some candidates believe that only science students can score high in mathematics, but this assertion is false. A social science student can do well in this subject if he/she prepares well and follow the first 3 points that I give above.
Question and Answer
Question 1
Tanθ = 5/4, find sin2θ – cos2θ
A. 41/9 B. 9/41 C. 1 D. 5/4
Answer
Recall,
Tanθ = opposite/adjacent
Opposite = 5
Adjacent = 4
Also,
(Hypotenuse)2 = (opposite)2 + (adjacent)2
(Hypotenuse)2 = 52 + 42 = 25 + 16 = 41
sin2θ = (opposite)2/(hypotenuse)2 = 25/41
cos2θ = (adjacent)2/(hypotenuse)2 = 16/41
sin2θ – cos2θ = 25/41 – 16/41 = 9/41
Question 2
In triangle XYZ, <XYZ = 15o, <XZY = 45o, |XY| = 7cm, find |YZ|
A. 7√2 cm B. 7cm C. 14√2 cm D. 7/2 √6 cm
Answer
To calculate, use sine rule
|XY|/sine (<XZY) = |YZ| / sine (<YXZ)
Note,
<YXZ + <XZY + <XYZ = 180 (sum of angles in a triangle)
<YXZ = 180 – 15 – 45 = 120
7/sine 45 = |YZ| / sine 120
sine 45 = 1/√2
sine 120 = √3 /2
7√2 = 2 |YZ| / √3
7√6 / 2 = |YZ|
|YZ| = 7/2 √6 cm
Question 3
The mean of the numbers 3, 6, 4, x, and 7 is 5. Find the standard deviation
A. 2 B. 3 C. √3 D. √2
Answer
Mean = (3 + 6 + 4 + x + 7) /5
5 = (3 + 6 + 4 + x + 7) /5
25 = 20 + x
X = 5
To calculate standard deviation,
((3-5)2 + (6-5)2 + (4-5)2 + (5-5)2 + (7-5)2)/5 = (4 +1+1+0+4) /5 = 10/5 = 2
Then, find the square root
S.D = √2
Question 4
A cinema hall contains a certain number of people. If 22 ½ % are children, 47 ½% are men and 84 are women. Find the number of men in the hall.
A. 133 B. 113 C. 63 D. 84
Answer
Percentage of children + men + women = 100
Let x be the percentage of women
22 ½ % + 47 ½% + x = 100
X = 100 – 70 = 30%
Let the total number of people in the cinema hall be Y
30% of Y = 84 for women
i.e.
30/100 x Y = 84
8400/30 = Y
Y = 280
Number of men,
47 ½% of 280
95/200 x 280 = 133
Recommended: JAMB MATHEMATICS PAST QUESTIONS AND ANSWERS
Question 5
Find the derivative of y = sin2(5x) with respect to x
A. 2sin5xcos5x B. 5sin5xcos5x C. 10sin5xcos5x D. 15sin5xcos5x
Answer
Y = (sin(5x))2
Let u = sin5x
Let a = 5x
Da/dx = 5
U = sina
Du/da = cos a
Du/dx = da/dx x du/da = 5 x cosa = 5cosa = 5cos5x
Y = u2
Dy/du = 2u
So,
Dy/dx = dy/du x du/dx = 5cos5x x 2u = 10ucos5x
Since u = sin5x
Dy/dx = 10sin5xcos5x
