F(x) = 4 [cos (x)]^2 - 3 = 0
4[cos(x)]^2 = 3
cos(x) = √3 / 2
That happens in the first and fourth quadrants, for the angles 30 degrees and 330 degrees.
Answer: x = 30 degrees and x = 330 degrees
Answer:
2.25 and 4.95
Step-by-step explanation:
x + y = 7.2
x - y = 2.7
x = 7.2 - y
x - y = 2.7
(7.2 - y) - y = 2.7
7.2 - 2y = 2.7
-2y = 2.7 - 7.2
-2y = -4.5
-2y/-2 = -4.5/-2
y = 2.25
x + y = 7.2
x + 2.25 = 7.2
x = 7.2 - 2.25
x = 4.95
Check: 4.95 and 2.25
x + y = 7.2
(4.95) + (2.25) = 7.2
7.2 = 7.2
x - y = 2.7
(4.95) - (2.25) = 2.7
2.7 = 2.7
Answer: -2x + 3/2
Step-by-step explanation:
Simplify the expression.
Answer:
Below in bold
Step-by-step explanation:
The sequence is:
3, x, y, 18
If this is an A P then
x - 3 = y - x
2x - y = 3 (A) and
y - x = 18 - y
2y - x = 18 (B)
Multiply (A) by 2:
4x - 2y = 6 (C)
Adding B and C:
3x = 24
x = 8.
and
2y - 8 = 18
2y = 26
y = 13.
So x = 8 and y = 13.
b) ar + ar^2 = 6ar^3 where a = first term and r = common ratio
Divide by a:
r + r^2 = 6r^3
6r^3 - r^2 - r = 0
r(6r^2 - r - 1) = 0
r(3r + 1)(2r - 1) = 0
So the 2 possible values of r
= -1/3 and 1/2.
i) The common ratio is positive so it must be 1/2.
Second term ar = 8
1/2 a = 8
a = 16.
So the first 6 terms are:
16, 8, 4, 2, 1, 1/2.
Answer: B
Step-by-step explanation:
