The equation x 2-4 x - c -0 has real roots- then c - 4A- c - 4B- c - 4

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Standard X

Mathematics

Factorisation of Quadratic Polynomials - Factor Theorem

The equation ...

Question

The equation $x^{2} + 4 x + c = 0$ has real roots, then $c \geq 4$ .

c ≥ 4

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c ≤ 4

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Solution

The correct option is B
c ≤ 4

Step 1:- For $x^{2} + 4 x + c = 0$ , the value of discriminant $D = 4^{2} - 4 c = 16 - 4 c$

Step 2:- The roots of quadratic equation are real only when $D \geq 0$

$16 - 4 c \geq 0$

Step 3:- $c \leq 4$

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The equation x2+4x+c=0 has real roots, then c≥4.

The correct option is B c ≤ 4 Step 1:- For x2+4x+c=0, the value of discriminant D=42–4c=16−4c Step 2:- The roots of quadratic equation are real only when D≥0 16–4c≥0 Step 3:- c≤4

The equation $x^{2} + 4 x + c = 0$ has real roots, then $c \geq 4$ .

The correct option is B
c ≤ 4

Step 1:- For $x^{2} + 4 x + c = 0$ , the value of discriminant $D = 4^{2} - 4 c = 16 - 4 c$

Step 2:- The roots of quadratic equation are real only when $D \geq 0$

$16 - 4 c \geq 0$

Step 3:- $c \leq 4$