<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>
1 kilometer is 1000 (or 10^3) meters, so Eric walks .81*10^3=810 meters and YiTing walks .65*10^3=650 meters.
Answer:
Step-by-step explanation:
definition-when two lines are crossed by another line the angles in matching corners are corresponding angles
pls mark me brainliest
Answer: Write the expression as a -90,
O Substitute 102 in for the variable, a.
Simplify by subtracting 90 from 102.
Step-by-step explanation:
The answer is 12.
subtract
