JAMB Mathematics Past Questions & Answers - Page 414

2,066.

Evaluate 21.05347 - 1.6324 x 0.43 to 3 decimal places

20.980

20.351

20.981

20.352

Correct answer is D

Hint: Use BODMAS, in other words, do multiplication of the second and the last first before subtracting value obtained from the first.

2,067.

The expression ax² + bx + c equals 5 at x = 1. If its derivative is 2x + 1, what are the values of a, b, c respectively?

1, 3, 1

1, 2, 1

2, 1, 1

1, 1, 3

View answer & explanation

Correct answer is D

At x = 1, substituting x = 1 in the equation: ax² + bx + c = 5;
f(1) => a + b + c = 5 .....(1)

Taking the first derivative of f(x) in the original equation gives dy/dx = 2ax + b = 2x + 1 (given)....(2)

From (2),=> b = 1, and 2ax = 2x, => a = 1.

substituting into (1) 1 + 1 + c = 5, => c = 5 - 2 = 3

Thus a = 1, b = 1 and c = 3

2,068.

A function f(x) passes through the origin and its first derivative is 3x + 2. What is f(x)?

y = (3x²/)2 + 2x

y = (3x²)/2 + x

y = 3x² + (x/2)

y = 3x² +2x

View answer & explanation

Correct answer is A

Hints:
1. Integrate the given first derivative of f(x) at the boundaries, (0,0)

Then solve accordingly to get f(x) = y = (3x²/)2 + 2x

2,069.

In how many ways can a delegation of 3 be chosen from among 5 men and 3 women, if at least one man and at least one woman must be included?

View answer & explanation

Correct answer is D

No of ways of choosing 1 man, 2 women = 5C1 x 3C2
No of ways of choosing 2 men, 1 woman = 5C2 x 3C1
Summing, => (5C1 x 3C2) + (5C2 x 3C1) = 15 + 30 = 45

2,070.

Find the sum of the range and the mode of the set of numbers 10, 9, 10, 9, 8, 7, 7, 10, 8, 10, 8, 4, 6, 9, 10, 9, 10, 9, 7, 10, 6, 5