Question

Evaluate the expression. Assume that all the angles are in Quadrant I. (cos (arctan √3/7))

Answer 1

y = 0.971.

Explanation:

Given the expression (cos (arctan √3/7)) which all lies in the first quadrant. Note that all the trigonometry identities (sin, cos and tan) are all positive in the first quadrant.

From the expression given

(cos (arctan √3/7)), we need to get the expression in parenthesis first.

Let y = (cos (arctan √3/7))

If u = arctan √3/7

Then y = cos(u) .... 1

Let's get the value of u first

u = arctan √3/7

u = arctan(0.2474)

u = 13.896°

Substituting u = 13.896° into equation 1, we will have;

y = cos(u)

y = cos13.896°

y = 0.971.

Answer 2

0.971

Explanation:

Given the expression (cos (arctan √3/7)) which all lies in the first quadrant. Note that all the trigonometry identities (sin, cos and tan) are all positive in the first quadrant.

From the expression given

(cos (arctan √3/7)), we need to get the expression in parenthesis first.

Let y = (cos (arctan √3/7))

If u = arctan √3/7

Then y = cos(u) .... 1

Let's get the value of u first

u = arctan √3/7

u = arctan(0.2474)

u = 13.896°

Substituting u = 13.896° into equation 1, we will have;

y = cos(u)

y = cos13.896°

y = 0.971.

Hence the expression (cos(arctan√3/7)) is equivalent to 0.971