SOLUTION: Q. If x-1/x=3 find the value of 1. x^4+1/x^4 2. X^2+1/x^2 3. (X+1/x)^2 Q. if a+1/a=7 find the value of 1.a^2+1/a^2 2.(a-1/a)^2 3. a^4+1/a^4 Q. If x+1/x=4, show that

Algebra.Com
Question 1092206: Q. If x-1/x=3 find the value of
1. x^4+1/x^4 2. X^2+1/x^2 3. (X+1/x)^2
Q. if a+1/a=7 find the value of
1.a^2+1/a^2 2.(a-1/a)^2 3. a^4+1/a^4
Q. If x+1/x=4, show that x^2+1/x^2=14

Answer by greenestamps(13200)   (Show Source): You can put this solution on YOUR website!

I'll show you a couple of these so you can get the idea of how to work them. Then you can try the others yourself.

The last question is the easiest one to use to show you the general concept for working this kind of problem. In that problem we are given



and we are to show that



Observe what happens when you square both sides of the given equation. When you square the binomial on the left, the middle term is a constant. That is the general principle that lets you solve problems like this.





Now let's look a bit at your second problem. There you are given



and you are asked to find the values of

1. a^2+1/a^2
2.(a-1/a)^2
3. a^4+1/a^4

Finding the first of these will be exactly like the example worked above. For the second one, note that



so that one will be easy after you have solved the first one. And for the third of these, you can get the answer in a similar fashion by squaring your answer for the first one.

RELATED QUESTIONS

3/(x+1) +4/(x-2)=(px+q)/(x+1)(x-2) What is the value of p and q? (answered by mananth)
If x^2 + 1/x^2 =102, find the value of x^3 -... (answered by rothauserc,ikleyn)
find a value of x so that the sum is equal to one- 1) 1/x + 2/x 2) 4/x + 3/2x... (answered by robertb)
if x^2 + 1/x^2 =4 , then find the value of x^3 + 1/x^3 (answered by richard1234)
If x + 1/x = 4, find the value of x^2 + 1/x^2 (answered by greenestamps,ikleyn)
If (x+(1/x))^2 = 7 and x is a positive real number, find the exact value of x^3 + 1/x^3 (answered by ikleyn)
if x+1 is a factor of x^3+3x^2+kx+4, find the value of... (answered by Boreal,ikleyn)
Suppose x is a positive number such that {{{x^2=1-x}}}. There is a unique choice... (answered by ikleyn,MathTherapy)
if x=sqrt{3+2sqrt(2)} then find the value of x^2+1/x^2 and... (answered by mananth)