I’m not gonna play today at the same time
Answer: 14.73
Step-by-step explanation:
The given triangle is a right angle triangle.
EF^2 + DF^2 = ED^2
The hypotenuse is |ED| while the two shorter legs are |EF| and |DF|.
We can then apply the Pythagoras Theorem to find the length of EF.
(EF)^2 + (DF)^2 = (ED)^2
(EF)^2 + (12)^2 = (19)^2
(EF)^2 + 144 = 361
(EF)^2 = 361 - 144
(EF)^2 = 217
EF = 14.73
You move the decimal point forward until it reaches the one so it looks like this:
1.4 x 10⁵
the exponent, 5, just tells you how many spaces the decimal point moved.
<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>
