Hello, first post,

This is the question everyone is stuck on for our Year 11 Maths C assignment on Matrices and Applications.

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Question 4a and b.

Looking at 4a, its really simple with basic surds and I have already verified that it equals Square Root 2.

For question 4b, I used (1-x)^-1/2=SquareRoot(2) and solved x for 1/2. I then subbed in x=1/2 into the first 4 terms of the Power Series Expansion and got 1.383. I seriously thought I got it cos 1.383 is a pretty decent approximation for SquareRoot(2). I worked absolute error for this to be 0.087311.

Our teacher said this is wrong. She said you aren't meant to solve for X but apply the equation you have verified in 4a into the power series for question 4b. I'm so confused and I don't really get what she means by that.

First post so I don't know what to expect but I was pretty desperate to write this and come here haha. Any help would be very appreciated.