If x=2 and x=0 are roots of the polynomial f(x) = 2x³-5x² + ax+b find the value of a and b
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f(x) = 2x^3 - 5x^2 +ax + b
=> f(0) = 0
=> 2(0) - 5(0) +a(0) + b = 0
=> b = 0 ------(1)
Now,
f(2) = 0
=> 2(2)^3 - 5(2)^2 + a(2) + b = 0
=> 16 - 20 + 2a + b = 0
=> 2a + b = 4
=> 2a + 0 = 4 [ using equation 1]
=> 2a = 4
=> a = 2
=> f(0) = 0
=> 2(0) - 5(0) +a(0) + b = 0
=> b = 0 ------(1)
Now,
f(2) = 0
=> 2(2)^3 - 5(2)^2 + a(2) + b = 0
=> 16 - 20 + 2a + b = 0
=> 2a + b = 4
=> 2a + 0 = 4 [ using equation 1]
=> 2a = 4
=> a = 2
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