Answer:
x = 9
Step-by-step explanation:
The trick here is knowing that JKM and MKL are equal, which means MKL is equal to JKL/2. From that knowledge, we can solve.
MKL = JKL/2
5x + 1 = 46
5x = 45
x = 9
Answer:
Its 80
Step-by-step explanation:
80 x 15%=12
Recall the double/half angle formulas:
![\cos^2\dfrac x2=\dfrac{1+\cos x}2](https://tex.z-dn.net/?f=%5Ccos%5E2%5Cdfrac%20x2%3D%5Cdfrac%7B1%2B%5Ccos%20x%7D2)
![\sin^2\dfrac x2=\dfrac{1-\cos x}2](https://tex.z-dn.net/?f=%5Csin%5E2%5Cdfrac%20x2%3D%5Cdfrac%7B1-%5Ccos%20x%7D2)
We're given
, and since
is between π/2 and π, we expect
to be negative. So from the Pythagorean identity, we find
![\sin^2u+\cos^2u=1\implies\cos u=-\sqrt{1-\sin^2u}=-\dfrac7{25}](https://tex.z-dn.net/?f=%5Csin%5E2u%2B%5Ccos%5E2u%3D1%5Cimplies%5Ccos%20u%3D-%5Csqrt%7B1-%5Csin%5E2u%7D%3D-%5Cdfrac7%7B25%7D)
Also, we know
will fall between π/4 and π/2, so both
and
will be positive. Then we find
![\cos\dfrac u2=\sqrt{\dfrac{1+\cos u}2}=\dfrac35](https://tex.z-dn.net/?f=%5Ccos%5Cdfrac%20u2%3D%5Csqrt%7B%5Cdfrac%7B1%2B%5Ccos%20u%7D2%7D%3D%5Cdfrac35)
![\sin\dfrac u2=\sqrt{\dfrac{1-\cos u}2}=\dfrac45](https://tex.z-dn.net/?f=%5Csin%5Cdfrac%20u2%3D%5Csqrt%7B%5Cdfrac%7B1-%5Ccos%20u%7D2%7D%3D%5Cdfrac45)
and it follows that
![\tan\dfrac u2=\dfrac{\sin\frac u2}{\cos\frac u2}=\dfrac43](https://tex.z-dn.net/?f=%5Ctan%5Cdfrac%20u2%3D%5Cdfrac%7B%5Csin%5Cfrac%20u2%7D%7B%5Ccos%5Cfrac%20u2%7D%3D%5Cdfrac43)
in short, 25% is just 1/4 of anything, we know she's sold 25% which is $600, so her daily goal must be 1/4 + 1/4 + 1/4 + 1/4, or namely 600 + 600 + 600 + 600 = 2400.