Answer with explanation:
Given a function, y=f(x)
The Set of values that ,x can take for which y is defined is called domain of the function.
And,the set of values that ,y can take for which x ,is defined is called range of function.
For example:→Consider the function, y=x²
→y is defined for all values of x,so Domain is set of real numbers.→(-∞,∞)
→x is defined for positive values of y,so range of this function is [0, ∞).
A:→ y =sec x
Range =(-∞,-1]∪[1,∞)
B: →y=Cosec x
Range =(-∞,-1]∪[1,∞)
C:→y=tan x
Range =(-∞,∞)
D:→y=cot x
Range=(-∞,∞)
→→Option C and D⇒Tan x and Cot x, are trigonometric function ,whose range are set of all Real Numbers.