First lets see the pythagorean identities

So if we have to solve for sin theta , first we move cos theta to left side and then take square root to both sides, that is

Now we need to check the sign of sin theta
First we have to remember the sign of sin, cos , tan in the quadrants. In first quadrant , all are positive. In second quadrant, only sin and cosine are positive. In third quadrant , only tan and cot are positive and in the last quadrant , only cos and sec are positive.
So if theta is in second quadrant, then we have to positive sign but if theta is in third or fourth quadrant, then we have to use negative sign .
Answer:
a
Step-by-step explanation:

<h3>area of shaded figure= </h3>
<h2>area of whole rectangle</h2>
= lengthx breadth=15x30= 450 cm²
<h3>area of unshaded region= lengthx breadth= (30-8)x 15cm²= 22x 15cm²= 330cm²</h3>
<h3>are of shaded region</h3>
= area of whole rectangle -area of unshaded region= 450cm²-330cm²= 120cm²
therefore 120 is correct answer
Answer:
its D
Step-by-step explanation:
Did the test
Question:
Diners frequently add a 15% tip when charging a meal to a credit card. What is the price of the meal without the tip if the amount charged is $20.70? How much was the tip?
Answer:
Price of meal = $18
Tip price = $2.70
Step-by-step explanation:
Let the price of the meal be <em>y</em>;
Let the tip be <em>t</em>
<em></em>
<em>From the question;</em>
15% of <em>y </em>is the tip charge (<em>t</em>). i.e
t = 15%y
=> t = 0.15y --------(i)
<em>The total amount charged is $20.70 (This means that the sum of the price of the meal and the tip is $20.70)</em>
=> y + t = 20.70 [substitute the value of t=0.15y from equation (i)]
=> y + 0.15y = 20.70
=> 1.15y = 20.70
=> y = 
=> y = $18
Therefore the price of the meal, y, is $18.
From equation (i),
t = 0.15y [substitute the value of y = $18]
t = 0.15(18)
t = $2.70
Therefore the tip was $2.70