Recall that for all t,
cos²(t) + sin²(t) = 1
Now,
x = 5 cos(t) - 7 ⇒ (x + 7)/5 = cos(t)
y = 5 sin(t) + 9 ⇒ (y - 9)/5 = sin(t)
so that substituting into the identity above, we get
((x + 7)/5)² + ((y - 9)/5)² = 1
which we can rewrite as
(x + 7)²/25 + (y - 9)²/25 = 1
(x + 7)² + (y - 9)² = 25
and this is the equation of a circle centered at (-7, 9) with radius 5.
The value of x in the equation 4(x + 5) = 9x + 4x − 34 is 6 after solving and applying properties.
<h3>What is a linear equation?</h3>
It is defined as the relation between two variables, if we plot the graph of the linear equation we will get a straight line.
If in the linear equation, one variable is present, then the equation is known as the linear equation in one variable.
We have equation:
4(x + 5) = 9x + 4x − 34 (Given)
4x +20 = 9x + 4x − 34 (Distributive Property)
4x +20 +34 -4x = 9x + 4x − 34 + 34 -4x (Subtraction Property of Equality)
54 = 9x + 4x − 34 + 34 -4x (Addition Property of Equality)
54 = 9x (Combine Like Terms)
x = 54/9 (Division Property of Equality)
x = 6
Thus, the value of x in the equation 4(x + 5) = 9x + 4x − 34 is 6 after solving and applying properties.
Learn more about the linear equation here:
brainly.com/question/11897796
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The problem says that <span>Brandon sights a helicopter above a building that is 200 feet away at an angle of elevation of 30 degrees. So, you can calculate the height asked, by following this procedure:
</span>
Tan(α)=Opposite leg/Adjacent leg
α=30°
Opposite leg=x
Adjacent leg=200 feet
When you substitute these values into the formula above (Tan(α)=Opposite leg/Adjacent leg), you have:
Tan(α)=Opposite leg/Adjacent leg
Tan(30°)=x/200
You must clear "x":
x=200xTan(30°)
Therefore, the value of "x" is:
x=115 feet
<span>
How high above the ground the is the helicopter?
The answer is: 115 feet</span>
If one shirt equals to $21.46, and you need to purchase 4 shirts to get the free pair of jeans, you multiply 4 by 21.46 and get 85.84. But if there is 42 customers taking advantage of the special, then you need to multiply 85.84 by 42, and you get 3,605.28.