questionr
Early access
Exams
Joint Entrance Examination
Mathematics
Complex Numbers
Question 368
Question 368 of 455
Medium
MCQ
If one root of
x
2
+
p
x
+
12
=
0
x^2+px+12=0
x
2
+
p
x
+
12
=
0
is 4, while
x
2
+
p
x
+
q
=
0
x^2+px+q=0
x
2
+
p
x
+
q
=
0
has equal roots, then the value of
q
q
q
is
A
4
B
12
C
3
D
49
4
\dfrac{49}4
4
49
Check answer
Press A-D to select · Enter to check
Solutions · 1
Post your solution
Official solution
16
+
4
p
+
12
=
0
⟹
p
=
−
7
16+4p+12=0 \implies p=-7
16
+
4
p
+
12
=
0
⟹
p
=
−
7
. Equal roots of
x
2
+
p
x
+
q
=
0
x^2+px+q=0
x
2
+
p
x
+
q
=
0
require
p
2
=
4
q
⟹
q
=
49
4
.
p^2=4q \implies q=\dfrac{49}4.
p
2
=
4
q
⟹
q
=
4
49
.
Answer the question to unlock
Previous
Next