Question:
If k is a root of x 2 – 4x + 1 = 0, then what is tan-1 k + tan-1 1 k equal to?
If k is a root of x 2 – 4x + 1 = 0, then what is tan-1 k + tan-1 1 k equal to?
Options:
- a) 2
- b) 0
- c) π 4
- d) π 2
- a) 2
- b) 0
- c) π 4
- d) π 2
correct answer : d)
Explanation:
x
2 – 4x + 1 = 0
Þ x = 23± > 0
Oswaal NDA/NA Year-wise Solved Papers
\ tan-1 k + tan-1 1
k
= tan-1 k k
k k
+
-×
1
1 1
tan-1 ¥ = 2
x
2 – 4x + 1 = 0
Þ x = 23± > 0
Oswaal NDA/NA Year-wise Solved Papers
\ tan-1 k + tan-1 1
k
= tan-1 k k
k k
+
-×
1
1 1
tan-1 ¥ = 2