128o
16o
64o
58o
Correct answer is A
Base angle of the triangle = 58°.
The third angle = 180° - (58° + 58°)
= 64°
Angle subtended at the centre = \(2 \times 64° = 128°\) (angle at the centre is twice the angle at the circumference).
2
4
√3
√2
1
Correct answer is A
x(x2 - 1) - x = 0
= x3 - 2x = 0
x(x2 - 2) = 0
x = 2
3
4
7
12
Correct answer is C
\(\begin{pmatrix} 2 & -3 \\ -1 & 4 \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} -1 \\ 8 \end{pmatrix}\)
\(\begin{pmatrix} 2x - 3y \\ -x + 4y \end{pmatrix} = \begin{pmatrix} -1 \\ 8 \end{pmatrix}\)
\(2x - 3y = -1 ... (i)\)
\(-x + 4y = 8 ... (ii)\)
From (ii), x = 4y - 8.
\(2(4y - 8) - 3y = -1 \implies 8y - 16 - 3y = -1\)
\(5y = -1 + 16 = 15 \implies y = 3\)
\(x = 4(3) - 8 = 12 - 8 = 4\)
\(\therefore x + y = 3 + 4 = 7\)
If X \(\ast\) Y = X + Y - XY, find x when (x \(\ast\) 2) + (x \(\ast\) 3) = 68
24
22
-12
-21
Correct answer is D
x \(\ast\) y = x + y - xy
(x \(\ast\) 2) + (x \(\ast\) 3) = 68
= x + 2 - 2x + x + 3 - 3x
= 86
3x = 63
x = -21
60
57
54
42
Correct answer is C
m \(\ast\) n = mn - n - 1, m \(\oplus\) n = mn + n - 2
3 \(\oplus\) (4 \(\ast\) 5) = 3 \(\oplus\) (4 x 5 - 5 - 1) = 3 \(\oplus\) 14
3 \(\oplus\) 14 = 3 x 14 + 14 - 2
= 54