Given that tan x =, find cos (90 - x)º giving the answer to 4 significant figures

You didn't state the value of tanx

suppose tanx = 4/5
using the standard x,y, and r definitions
tanØ = y/x
then r^2 = x^2 + y^2 = 16 + 25 = 41
then r = √41

but sinx = cos(90-x)°, (property of complementary angles)
so cos(90-x) = sinx = 4/√41
use your calculator to find that value correct to 4 significants

So whatever your given value is for tanx
simply follow the same steps

as Reiny noted, sinx = cos(90-x)

so, if you have tanx = y, then
cos(90-x) = sinx = 1/cscx = 1/√(1+cot^2x) = 1/√(1 + 1/y^2)

To find the value of cos(90 - x)º, we first need to determine the value of x.

Given that tan x = (an incomplete value was provided by the user), we know that the tangent of an angle is equal to the ratio of the opposite side to the adjacent side in a right triangle.

However, since we don't have the value for tan x, we cannot directly determine x. We will need additional information or values to solve for x.

If you provide the actual value for tan x, I can assist you further in finding cos(90 - x)º.