True
<span>Cos(A+B)=CosACosB-SinASinB
therefore Cos(A+A)= CosACosA - SinASinA
= Cos^2A - Sin^2A</span>
Answer:
x=90° and y=35°
Step-by-step explanation:
to get x and y first you must find the middle angles based on the information you have so:
35+90+n=180° solve for n to get what the middle angles are (since they are vertical angles they are equal) so the middle angles are both 55 degrees
and then 180-x=that angle that is also on the line with x so we'll call it k
so k+55+y=180°
we can see that y equals 35* because I noticed that those are parallel lines on the outside of the triangle so 35* and y angles are congruent and y =35°
now 35+55+k=180°
solve for the angle next to x which we called k and it is 90°
so x=90° and y=35°
after all this math I realized that if they are parallel lines then we can just use that to figure it out so use the properties to find out that x=90° and y=35°
<span>
<span>first off your answer is 21.90 and the step by step i wrote it for you:) Finding the
square root of a number is the inverse
operation of squaring that number. Remember, the square of a number
is that number times itself. </span>
The perfect
squares are the squares of the whole numbers.
The square root
of a number, n, written below is the number that gives n when multiplied by
itself.
</span> <span>Many mathematical
operations have an inverse, or opposite, operation. Subtraction is the opposite
of addition, division is the inverse of multiplication, and so on. Squaring,
which we learned about in a previous lesson (exponents),
has an inverse too, called "finding the square root." Remember, the
square of a number is that number times itself. The perfect squares are the
squares of the whole numbers: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 … </span>
The square root
of a number, n, written
<span>
is the number that gives n when multiplied by itself. For example,</span>
<span>because
10 x 10 = 100</span>
Examples
Here are the
square roots of all the perfect squares from 1 to 100.
Finding square
roots of of numbers that aren't perfect squares without a calculator
1. Estimate
- first, get as close as you can by finding two perfect square roots your
number is between.
2. Divide -
divide your number by one of those square roots.
3. Average -
take the average of the result of step 2 and the root.
<span>4. Use the result
of step 3 to repeat steps 2 and 3 until you have a number that is accurate
enough for you.
</span>
Example:
Calculate the square root of 10 ()
to 2 decimal places.
<span>1. Find
the two perfect square numbers it lies between.
</span>
<span><span>Solution:
</span><span>32
= 9 and 42 = 16, so
lies between 3 and 4.</span></span>
<span>2. Divide
10 by 3. 10/3 = 3.33 (you can round off your answer)</span>
<span>3. Average
3.33 and 3. (3.33 + 3)/2 = 3.1667</span>
<span>Repeat step
2: 10/3.1667 = 3.1579</span><span>Repeat step 3: Average 3.1579 and 3.1667. (3.1579 + 3.1667)/2 = 3.1623</span>
Try the answer
--> Is 3.1623 squared equal to 10? 3.1623 x 3.1623 = 10.0001
If this is accurate
enough for you, you can stop! Otherwise, you can repeat steps 2 and 3.
<span>Note:
There are a number of ways to calculate square roots without a calculator.
This is only one of them.</span>
<span><span>
</span>
</span>
<span>
<span />Example:
Calculate the square root of 10 ()
to 2 decimal places.
<span>1.
Find the two perfect square numbers it lies between.
</span>
<span><span>Solution:
</span><span>32
= 9 and 42 = 16, so
lies between 3 and 4.</span></span>
<span>2.
Divide 10 by 3. 10/3 = 3.33 (you can round off your answer)</span>
<span>3.
Average 3.33 and 3. (3.33 + 3)/2 = 3.1667</span>
<span>Repeat
step 2: 10/3.1667 = 3.1579
Repeat step 3: Average 3.1579 and 3.1667. (3.1579 + 3.1667)/2 = 3.1623</span>
<span>Try
the answer --> Is 3.1623 squared equal to 10? 3.1623 x 3.1623 =
10.0001</span>
If
this is accurate enough for you, you can stop! Otherwise, you can repeat steps
2 and 3.
</span>
<span>
<span><span>
<span> </span></span></span></span>
