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.
The minimum value of y in the equation y = x\(^2\) - 6x + 8 is
8
3
7
-1
Correct answer is D
y = x\(^2\) - 6x + 8
\(\frac{dy}{dx}\) = 2x - 6
\(\frac{dy}{dx}\) = 0
2x - 6 = 0
x = 3
\(\therefore\) y = 3\(^2\) - 6(3) + 8
= 9 - 18 + 8
= -1
Simplify \(\frac{x^2 - y^2}{2x^2 + xy - y^2}\)
\(\frac{x + y}{2x + y}\)
\(\frac{x + y}{2x - y}\)
\(\frac{x - y}{2x - y}\)
\(\frac{x - y}{2x + y}\)
Correct answer is C
\(\frac{x^{2} - y^{2}}{2x^{2} + xy - y^{2}}\)
\(2x^{2} + xy - y^{2} = 2x^{2} - xy + 2xy - y^{2}\)
= \(x(2x - y) + y(2x - y) \)
= \((x + y)(2x - y)\)
\(\frac{x^{2} - y^{2}}{2x^{2} + xy - y^{2}} = \frac{(x + y)(x - y)}{(x + y)(2x - y)}\)
= \(\frac{x - y}{2x - y}\)
Solve the inequality x - 1 > 4(x + 2)
x > -3
x < -3
2 < x < 3
-3 < x < -2
Correct answer is B
x - 1 > 4(x + 2) = x - 1 > 4x + 8 4x + 8 < x - 1 = 4x - x < -1 -8 = 3x < -9 ∴ x < -3
An (n - 2)2 sided figure has n diagonals. Find the number n diagonals for 25-sided figure
7
8
9
10
Correct answer is A
(n - 2)2 = 25
n - 2 = 25 = 5
n = 5 + 2
= 7
Find the values of y which satisfy the simultaneous equations x + y = 5, x2 - 2y2 = 1
-12, -2
-12, 12
-12, +2
2, -2
Correct answer is C
x + y = 5.......(i) x2 - 2y2 = 1.......(ii) x = 5 - y.........(iii) Subst. for x in eqn.(ii) = (5 - y)2 - 2y2 = 1 25- 10y + y2 - 2y2 = 1 25 - 1 = y2 + 10y y2 + 10y2 - 24 = 0 (y + 12)(y - 2) = 0 Then Either y + 12 = 0 or y - 2 = 0 = (-12, +2)