Arctangent is the inverse function of tangent. It is also written as arctan or tan-1. If y = tan x, then x = arctan y.
tan-1 1 = 450 or arctangent (1) = 450. This means that the angle 450 has tangent equal to 1.
Correct Answer: B
Step 1: Let B = arctan . Then tan B = .
Step 2: So, sec [arctan ] = sec [arctan(tan B)].
Step 3: = sec B
Step 4: From the figure, we observe that sec B = .
Step 5: So, sec[arctan ] = .