1.

If `alpha, beta, gamma` are the roots of the equation `x^3+ qx +r =0`then find the equation whose roots are (a) `alpha+beta, beta+gamma, gamma+alpha` (b) `alpha beta, beta gamma, gamma alpha`

Answer» a)`alpha+beta+gamma=0`
`alphabeta+betagamma+gammaalpha=q`
`alphabetagamma=-r`
`2(alpha+beta+gamma)=0=b`
`x^3-bx^2+cx-d=0`
`C=alphabeta+alphagamma+beta^2+betagamma+betaalpha+gamma^2+gammaalpha+alphabeta+alpha^2+alphabeta`
`c=(alpha+beta+gamma)^2+(alphabeta+gammabeta+alphagamma)`
`c=q`
`d=(alpha+beta)(beta+gamma)(gamma+alpha)`
`d=alphabeta+alphagamma+beta^2+betagamma)(alpha+gamma)`
`d=alphabetagamma+alphagamma^2+beta^2gamma+betagamma^2+alpha^2beta+alpha^2gamma+beta^2gamma+alphabetagamma`
`d=r`
`x^3+2x+r=0`
`b)b=alphabeta+betagamma+gammaalpha=q`
`c=alphabeta^2gamma+betagammaa^2alpha+alpha^2betagamma`
`=alphabetagamma(alpha+beta+gamma)=0`
`d=alpha^2beta^2gamma^2=r^2`
`x^3-qx^2+0x-r^2=0`
`x^3-qx^2-r^2=0`.


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