find the real solutions for the following quadratic equation: x^2+6x+3=0
\[\large \sin^{-1}(\sin \frac{7 \pi}{5}) \implies \color{green}{ \frac{7 \pi}{5}}\]
did they tell you a domain restriction?
What is the exact value of the following expression: sin^-1 (sin 11pie/8)
Looking at the last one, what do you think the answer is?
this is a function that is the inside of itself, what happens? f(f^(-1)(x)) = x
well the anwer is 7pie/5 but it had a range restriction of -pie/2, pie/2
does the second one?
yes it also has the same restrictions
the range restriciton makes it "go both ways" so that the inverse is also a fuction
then its the same deal
but according to the exact value it's not right because it can't be bigger than 1
o wait I read that wrong 1 sec
ok
ok the first one is wrong also, sorry. sin(7pi/5) is in the 3rd quad, but that is not within the domain of sin so when we go back it gives you the angle that is in the 4th quad
so sin^(-1)(sin(7pi/5)) = the anlge that is the same y value as 7pi/5 but in the 4th quad
make sense?
so take 7pi/5 and minus pi from it. this is how much you need to subtract from 0 to get the angle so the answer is -(7pi/5-pi) = sin^(-1)(sin(7pi/5)) = -2pi/5 = aprx -1.25664
and 11pi/8 is the same deal sin^(-1)(sin(11pi/8)) = -(11pi/8-pi)
wow
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