Answer:t=1
Step-by-step explanation:
16-2t=t+9+4t
Collect like terms
4t+2t+t=16-9
Combine like terms
7t=7
Divide both sides by 7
7t ➗ 7=7 ➗ 7
t=1
<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>
