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 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
B.
7110
P and q are the roots of the equation x2 – 30x + 221 = 0
Then, p + q = - ( - 30)/1 =30
p + q = 30 ... 1st eq.
and pq = 221 ...2nd eq.
after solving both equation, we get p = 17 and q = 13
now, we have to calculate the value of P3 + q3 = (17)3 + (13)3 = 4913 + 2197 = 7110
hence, option B is correct
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