Double angle (or half angle, depending how you look at it) identities:
So we have
Note that when taking the square root, we should take into account that that could yield two possible solutions, but we know 
and 
, so it's also the case that 
.
Also, the reason we have equality in the last step can be explained like so:
(not unlike the process used to complete the square)
Try this option:
answer is 18.
For more information see the attached picture.
Answer:
<u>It is 3</u>
Step-by-step explanation:
Multiplication is one of the four basic operations in arithmetic, along with addition, subtraction, and division. Multiplication can actually be considered repeated addition, and you can solve simple multiplication problems by adding repeatedly. For larger numbers, you'll want to do long multiplication, which breaks the process down into repeated simple multiplication and addition problems. You can also try a shortcut version of long multiplication by splitting the smaller number in the problem into tens and ones, but this works best when the smaller number is between 10 and 19.
- <u>Restate the problem as an addition problem. </u>
- <u>Add the repeated number together to get your answer. </u>
- <u>Switch to long multiplication when multiplying 2-digit or larger numbers.</u>
<u>
</u>
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672 cm³
Step-by-step explanation:
10x7x9=630
2x3x7=42
630+42=672
Answer:
y=3/4x+5.2
Step-by-step explanation:
y2-y1/x2-x1
6.5-0.5-=6
2--6=2+6=8 (2 negatives make a positive)
6/8 (simplify)=3/4
crosses y at 5.2
