Consider the following statements in respect of the quadratic equation 4(x - p)(x - q) - r2 = 0, where p, q and r are real numbers:
1) The roots are real
2) The roots are equal if p = q and r = 0
Where of the above statements is/are correct ?
1 only
2 only
Both 1 and 2
Neither 1 nor 2
How many real roots does the equation x2 + 3|x| + 2 = 0 have ?
1 only
2 Only
Both 1 and 2
Neither 1 nor 2
Under which one of the following conditions will the quadratic equation x2 + mx + 2 = 0 always have real roots ?
m2 8
m2
If x = 1 + i, then what is the value of x6 + x4 + x2 + 1 ?
6i - 3
- 6i + 3
- 6i - 3
6i + 3
C.
- 6i - 3
Given equation is x6 + x4 + x2 + 1
And x = 1 + i
Then x2 = (1 + i)2
⇒ x2 = 1 - 1 + 2i
⇒ x2 = 2i
We can simplify it as : x4(x2 + 1) + (x2 + 1) = (x2 + 1)(x4 + 1) = (x2 + 1)((x2 + 1)2 – 2x2))
Put the value of x2 in the above equation
= (2i + 1)((2i +1)2 - 4i))
= (2i + 1)( - 4 + 1 + 4i - 4i)
= (2i + 1)(- 3)
= - 6i - 3
Option C is correct.
If both p and q belong to the set {1, 2, 3, 4}, then how many equations of the form px2 + qx + 1 = 0 will have real roots ?
12
10
7
6
If p and q are the roots of the equation x2 – 30x + 221 = 0, what is the value of p3 + q3 ?
7010
7110
7210
7240
Let f(x) = x2 + 2x – 5 and g(x) = 5x + 30
Consider the following statements:
1) f[g(x)] is a polynomial of degree 3.
2) g[g(x)] is a polynomial of degree 2.
Which of the above statements is/are correct ?
1 only
2 only
Both 1and 2
Neither 1 nor 2