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4 x ^ 2 - 2 x + 1 the whole x + k + 4 is equals to zero find the value of k using the formula of discriminant |
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Answer» Answer: As it has real and EQUAL ROOTS, THEREFORE the DISCRIMINANT is zero. b 2 −4ac=0 ⇒(2(k+1)) 2 −4.4(k+1)=0 ⇒(2k+2) 2 −16(k+1)=0 ⇒4k 2 +8k+4−16k−16=0 ⇒4k 2 −8k−12=0 ⇒4(k 2 −2k−3)=0 ⇒k 2 −2k−3=0 ⇒k 2 −3k−k−3=0 ⇒k(k−3)+1(k−3)=0 ⇒(k−3)(k+1)=0 k−3=0 k+1=0 k=3 k=−1 ∴ The roots are 3 and −1. |
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