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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: estpl6 on March 27, 2017, 07:25:07 pm
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Hi all
First post, so please be nice. :) And hello everyone!
How do I use Ti Nspire to solve two defined functions simultaneously in a CAS active paper? I tried defining the functions and solving it, but it spits out gibberish. Thanks!
Question:
f(x) = x^4+ax^3 + bx^2 + 36x + 144
g(x)= x^4 +(a+3)x^3 - 23x^2 + (b+10)x + 40
both cross the x-axis at -2, determine the values of a and b.
Ans: a = -3, b = -28
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Hi!
You'd first solve this question by defining the two functions, like you've already done.
'Define f(x)= ..' and 'Define g(x)= ...'
Now on your CAS, if you press Menu, Algebra and then something called 'Solve system of equations' ( its around the bottom I think) it should pop up with a menu asking you how many equations you want to solve for. After inputting that number there should be two blank squares where you can put your equations.
Since you know that both of them cross the x-axis at -2 you can write
f(-2) = 0 and g(-2) = 0
Press enter and it should solve for a and b.
I don't have my CAS on me right now and the last time I did Methods was last year, so if I'm wrong please forgive me!! I'm pretty sure this is how you go about doing it though :').