1Find the foci of thw ellipse given by the equation x236 y26
1)Find the foci of thw ellipse given by the equation x^2/36 +y^2/64=1
2) solve for x write your answer in interval notation x^2-x >_30
3) express log (x^4/ 3cuberoot y) in the terms of log x and log y.
Solution
1. x2/36 + y2/64=1
Here the larger denominator is under y2,so its a vertical ellipse
It is of the form
(x-h)2/b2+(y-k)2/a2=1
Here (h,k)=(0,0)
b2=36 a2=64
c2=a2-b2= 64-36=28
c=2sqrt7
focii= (h,k+-c) =(0,0+-2sqrt7)= (0,+-2sqrt7)
2. x2-x>=30
x2-x-30>=0
(x-6)(x+5)>=30
critical points are x=6,-5
And the solution is
(-inf,-5]U[6,inf)
3. log(x4/3 cube root y)
log (a/b)=log a - log b
therefore log(x4/3cuberoot y)= log x4- log 3 cube root y = 4 log x - log3 - 1/3 log y
