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Mathematics 14 Online
OpenStudy (anonymous):

pls.....answer the 29th question...

OpenStudy (anonymous):

OpenStudy (ajprincess):

Let \(f(x)=x^3+3x^2-2\alpha x+\beta\). Since (x+1) is a factor of f(x), f(-1)=0. \(f(-1)=(-1)^3+3(-1)^2-2\alpha*(-1)+\beta\) \(0=-1+3+2\alpha+\beta\) \(0=2+2\alpha+\beta\) \(-2=2\alpha+\beta-(1)\) Since (x+2) is a factor of f(x), f(-2)=0. \(f(-2)=(-2)^3+3(-2)^2-2\alpha*(-2)+\beta\) \(0=-8+12+4\alpha+\beta\) \(0=4+4\alpha+\beta\) \(-4=4\alpha+\beta-(2)\) solve the simultaneous equations (1) and (2) to find \(\alpha\) and \(\beta\). can u do?

OpenStudy (anonymous):

no....@ajprincess

OpenStudy (anonymous):

sry...need HELP @ajprincess

OpenStudy (ajprincess):

\(-2=2\alpha+\beta-(1)\) \(-4=4\alpha+\beta-(2)\) \((2)-(1)=>-2=2\alpha\) \(\alpha=-2/2\) \(\alpha=-1\) Plug in the value of \(\alpha\) in equation (1) to find \(\beta\)

OpenStudy (anonymous):

\[wher did \beta go\i n the calculation\]

OpenStudy (anonymous):

@ajprincess

OpenStudy (ajprincess):

\((2)-(1)=>-4-(-2)=4\alpha+\beta-2\alpha-\beta\) \(-4+2=2\alpha\) \(-2=2\alpha\) \(\alpha=-2/2\) \(\alpha=-1\)

OpenStudy (ajprincess):

is it clear nw @basith?

OpenStudy (anonymous):

yes..thnx 4 tht.can u help me with the second part of the question also

OpenStudy (anonymous):

@ajprincess

OpenStudy (ajprincess):

jst a minute. am takng a look at it

OpenStudy (anonymous):

k

OpenStudy (ajprincess):

First find the factors of -5. They are -1,5,1 and -5. Let f(x)=x^3-3x^2-9x-5 See for which of the values f(x) be zero when u substitute for x.

OpenStudy (anonymous):

sry g2g......anyway thnx... :)

OpenStudy (ajprincess):

that's k. yw:)

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