if x is equal to 5 - 2 under root 6 find x power cube plus one upon x ...
**Solution:**
To find the value of x, we have the equation:
x = 5 - 2√6
To simplify this expression, we need to rationalize the denominator of the radical term. The conjugate of 2√6 is -2√6, so we can multiply both the numerator and denominator by -2√6:
x = (5 - 2√6) * (-2√6) / (-2√6)
Expanding and simplifying, we get:
x = (-10√6 + 4 * 6) / (-12)
x = (-10√6 + 24) / (-12)
x = (24 - 10√6) / (-12)
x = -2 + (5/2)√6
So, x is equal to -2 + (5/2)√6.
Now, let's find x^3 + 1/x^3.
Substituting the value of x we found earlier, we have:
x^3 + 1/x^3 = (-2 + (5/2)√6)^3 + 1/(-2 + (5/2)√6)^3
Expanding and simplifying this expression may be quite complex, so let's use a shortcut.
We can use the formula for the sum of cubes:
(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3
Using this formula, we can rewrite x^3 as:
x^3 = (-2 + (5/2)√6)^3
x^3 = (-2)^3 + 3(-2)^2((5/2)√6) + 3(-2)((5/2)√6)^2 + ((5/2)√6)^3
Simplifying further, we have:
x^3 = -8 + 60√6 - 150 + (125/8)√6
x^3 = -158 + (173/8)√6
Similarly, we can find 1/x^3 as:
1/x^3 = 1/(-2 + (5/2)√6)^3
1/x^3 = 1/(-158 + (173/8)√6)
Now, we can evaluate the expression x^3 + 1/x^3:
x^3 + 1/x^3 = (-158 + (173/8)√6) + (1/(-158 + (173/8)√6))
Simplifying this expression may require further calculations, but this is the general process to find x^3 + 1/x^3 using the given value of x.
if x is equal to 5 - 2 under root 6 find x power cube plus one upon x ...
To make sure you are not studying endlessly, EduRev has designed Class 9 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 9.