If cos (x + 25)o = sin 45o, find the value of x
20
30
45
60
Correct answer is A
cos(x + 25o) = sin 45o
using cos \(\theta\) = sin(90 - \(\theta\))
cos(x + 25o) = cos(90 - 45)
cos(x + 25o) = cos 45
x + 25 = 45
x = 45 - 25
x = 20o
If tan x = 1, evaluate sin x + cos x, leaving your answer in the surd form
2\(\sqrt{2}\)
\(\frac{1}{2} \sqrt{2}\)
\(\sqrt{2}\)
2
Correct answer is C
tan x = 1; x = tan-1(10 = 45o
sin x + cos x
= sin 45o + cos 45o
= \(\frac{\sqrt{2}}{2} + \frac{\sqrt{2}}{2}\)
= \(\frac{\sqrt{2} + \sqrt{2}}{2}\)
= \(\frac{2\sqrt{2}}{2}\)
= \(\sqrt{2}\)
If xo is obtuse, which of the following is true?
x . 90
180 < x < 270
x < 90
90 < x < 180
Correct answer is D
obtuse angle \(\to\) 90o < x < 180o
The angles of a quadrilateral are (x + 10)o, 2yo, 90o and (100 - y)o, Find y in terms of x
y = 160 + x
y = 100 + x
y = 160 - x
y = x - 100
Correct answer is C
Sum of the angles in a quadrilateral = 360o
(x + 10o) + 2y + 90o + 100 - y = 360o
x + y + 200 = 360o
y = 360 - 200 - x
y = 160 - x
If the volume of a cube is 343cm3, find the length of its side
3cm
6cm
7cm
96cm
Correct answer is C
Volume of a cube = (side)3
= (side)3
(side)3 = 343
side = 3\(\sqrt{343}\)
side = 7cm