x, y and z are consecutive terms in a geometric sequence. If x+y+z =7/3, and x^2 + y^2 + z^2 = 91/9, find the values of x, y and z.
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Originally Posted by HelenaStage x, y and z are consecutive terms in a geometric sequence. If x+y+z =7/3, and x^2 + y^2 + z^2 = 91/9, find the values of x, y and z. The general form of a geometric series is So , and y in the next term so and So And the second equation tells us So you just have to solve those equations
Originally Posted by artvandalay11 The general form of a geometric series is So , and y in the next term so and So And the second equation tells us So you just have to solve those equations How? By substitution I get a quite complicated equation with radicals...
it seems to me that the best way to go about it is substitute for x, and yes it is going to get messy using an equation solver it looks like x=1/3 and r=-3 or x=3 and r=-1/3 so those are the solutions you should get
Originally Posted by HelenaStage How? By substitution I get a quite complicated equation with radicals... HI You might not like this --- 1 --- 2 From 1 --- 3 so now 3/2 Since its a quartic , Let p=-1(ommitted) , - therefore r=-3 , -1/3 so now head back to find x .
Oh, i substituted before squaring...^^
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