If x=1/2+√3 find the value of 2x³-7x²-2x+5
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P(1/2+root3)=2(1/2+root3)^3-7(1/2+root3)^2-2(1/2+root3)+1
expand with the identities(a+b)^3 and (a+b)^2
expand with the identities(a+b)^3 and (a+b)^2
Answered by
4
X=1/2+√3
Rationalising the denominator
1/2+√3* 2-√3/2-√3
2-√3/1
Putting value of x in equation
2*(2-√3) whole cube-7*(2-√3)whole square-2*(2-√3) +5
2*(2-√3)-7-4+2√3+5
4-2√3-7-4+2√3+5
-7+5
-2
Rationalising the denominator
1/2+√3* 2-√3/2-√3
2-√3/1
Putting value of x in equation
2*(2-√3) whole cube-7*(2-√3)whole square-2*(2-√3) +5
2*(2-√3)-7-4+2√3+5
4-2√3-7-4+2√3+5
-7+5
-2
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