Mathematics
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OpenStudy (anonymous):
I don't understand question 3c in the following post
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OpenStudy (anonymous):
OpenStudy (stamp):
What is the equation in question?
OpenStudy (anonymous):
the one in part b
hartnn (hartnn):
so, you got till t+1/t=4
right ?
now multiply both sides by 't' , what u get ?
OpenStudy (anonymous):
t^2 + 1 = 4t
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hartnn (hartnn):
so, can u solve the quadratic equation
t^2-4t+1=0 ??
OpenStudy (anonymous):
(t-2)^2 - 3
hartnn (hartnn):
(t-2)^2 = 3
take square root on both sides.
hartnn (hartnn):
actually u get
\(t - 2 =\pm \sqrt{(3)}\)
OpenStudy (anonymous):
yes my mistake
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hartnn (hartnn):
which completes part c
hartnn (hartnn):
have douts on part d also ?
hartnn (hartnn):
*doubts
OpenStudy (anonymous):
i thought i had to sub in t from the previous answer
OpenStudy (anonymous):
and i didnt understand how to solve for x
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hartnn (hartnn):
yes.
\(t =2\pm \sqrt{(3)} \\ (\sqrt{2+\sqrt3})^x=2\pm \sqrt{(3)}\)
OpenStudy (anonymous):
so x = 2
hartnn (hartnn):
\( (\sqrt{2+\sqrt3})^x=2\pm \sqrt{(3)} \\ (\sqrt{2+\sqrt3})^x=2+ \sqrt{(3)} \\ and \\ (\sqrt{2+\sqrt3})^x=2- \sqrt{(3)}\)
hartnn (hartnn):
for
\( (\sqrt{2+\sqrt3})^x=2+ \sqrt{(3)}\)
you get x=2, correct
hartnn (hartnn):
what about \( (\sqrt{2+\sqrt3})^x=2- \sqrt{(3)}\)
?
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OpenStudy (anonymous):
2-sqrt3 = 1/(2+sqrt3) is that right
hartnn (hartnn):
yes, use that.
hartnn (hartnn):
2-sqrt3 = 1/(2+sqrt3) = (2+sqrt3)^(-1)
OpenStudy (anonymous):
x = -3
hartnn (hartnn):
-3 ?? O.o
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hartnn (hartnn):
how ?
OpenStudy (anonymous):
wait its -2
hartnn (hartnn):
\(\checkmark\)
good :)
OpenStudy (anonymous):
thanks for your help, you're a lifesaver ;D
hartnn (hartnn):
welcome ^_^