This may be the answer,hope it helps
To solve this, I used guess and check.
I started by finding 60²=3600 and 70²=4900. 70² is too much, so I then did 65²=4,225.
After 65², I did 62²=3,844. I knew that was pretty close, so I did 64. 64²=4,096 and 63²=3,969. So, 64² was it.
4,096-4015=81
So, you would need to add 81 to 4015 in order to receive a perfect square, which is 64²(4,096).
Simplify the following:
-5×1×11×4
-5×1 = -5:
-5×11×4
-5×11 = -55:
-55×4
-55×4 = -220:
Answer: -220
<span>exact value of sin 157.5 without using a calculator
sin(157.5)=sin(315/2)
Identity: sin(x/2)=±√[(1-cosx)/2]
select positive identity since 175 is in the 2nd quadrant where sin>0
sin(315/2)=√[(1-cos315)/2]
cos 315=cos45 in quadrant IV=√2/2
sin(315/2)=√[(1-√2/2)/2]=√[(2-√2)/4]=√(2-√2)/2
sin(157.5)=√(2-√2)/2
check using calculator:
sin157.5º≈0.382...
√(2-√2)/2≈0.382...</span>
