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# S2 June 2014R Edexcel Question 7d watch

1. I have looked at the mark scheme and model answers and I don't get how you do this part.

https://www.dropbox.com/s/mig8e80egs...04.12.png?dl=0
2. (Original post by atoner420)
I have looked at the mark scheme and model answers and I don't get how you do this part.

https://www.dropbox.com/s/mig8e80egs...04.12.png?dl=0
You have E(R) = E(aX^2 + bX) = aE(X^2) + bE(X), which you should be able to work out.
3. (Original post by HapaxOromenon3)
You have E(R) = E(aX^2 + bX) = aE(X^2) + bE(X), which you should be able to work out.
Thanks man, I got it now. I had just never come across a question like it and it confused me lol.

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