Answer:
cos2θ = -0.7041
Cos θ = -0.3847
Step-by-step explanation:
Firstly, we should understand that since θ is in quadrant 2, the value of our cosine will be negative. Only the sine is positive in quadrant 2.
Now the sine of an angle refers to the ratio of the opposite to the adjacent. And since there are three sides to a triangle, we need to find the third side which is the adjacent so that we will be able to evaluate the cosine of the angle.
What to use here is the Pythagoras’ theorem which states that the square of the hypotenuse is equal to the sum of the squares of the adjacent and the opposite.
Since Sine = opposite/hypotenuse, this means that the opposite is 12 and the hypnotist 13
Thus the adjacent let’s say d can be calculated as follows
13^2 = 12^2 + d^2
169 = 144 + d^2
d^2 = 169-144
d^2 = 25
d = √25 = ±5
Since we are on the second quadrant, the value of our adjacent is -5 since the x-coordinate on the second quadrant is negative.(negative x - axis)
The value of cos θ = Adjacent/hypotenuse = -5/13
Cos θ = -5/13
Cos θ = -0.3846
Using trigonometric formulas;
Cos 2θ = cos (θ + θ) = cos θ cos θ - sin θ sin
θ = cos^2 θ - sin^2 θ
Cos 2θ = (-5/13)^2 - (12/13)^2
Cos 2θ = 25/169 - 144/169
Cos 2θ = (25-144)/169 = -119/169
Cos 2θ = -0.7041
Answer:
$94.05
Step-by-step explanation:
Original price of jeans=$95
Discount=10%
New price=(100% - 10%) of $95
=90% × 95
=90/100 × 95
=0.9 × 95
=$85.5
Sales tax of 10%
10% of the new price
=10/100 × 85.5
=0.1 × 85.5
=$8.55
Sales tax =$8.55
Total amount paid for the jeans= sales tax + new tax
=$8.55 + $85.5
=$94.05
Answer:
x = 63
Step-by-step explanation:
Simplifying
x + -18 = 45
Reorder the terms:
-18 + x = 45
Solving
-18 + x = 45
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '18' to each side of the equation.
-18 + 18 + x = 45 + 18
Combine like terms: -18 + 18 = 0
0 + x = 45 + 18
x = 45 + 18
Combine like terms: 45 + 18 = 63
x = 63
Simplifying
x = 63
Answer:
The answer is D
Step-by-step explanation:
Each blue dot over the number represents that number one time. There is one bot over 145 so there is only one 145. There are 5 dots over 165, so you write 165 five times and so on.
Answer:
its 43
Step-by-step explanation:
i had a test with the same question, i promise its right :)
