I need help plz. I have been trying to find these answers for awhile to.

to three decimal places , find the value of the first positive x-intercept for the function f(x)=2cos(x+4).

a . 1.712 ( this was my choice and was wrong)
b . 0.712
c . -2.429
d . -2.712

Question

I need help plz. I have been trying to find these answers for awhile to. 

to three decimal places , find the value of the first positive x-intercept for the function f(x)=2cos(x+4).

a . 1.712  ( this was my choice and was wrong)
b . 0.712
c . -2.429
d . -2.712

anonymous · Answer

https://www.ma.utexas.edu/users/jdanciger/fall2011/HW7-soln.pdf This website should help.

anonymous · Answer

A box is to be constructed from a sheet of cardboard that is 20 cm by 50 cm by cutting out squares of length x by x from each corner and bending up the sides. What is the maximum value could have? the answer is not 1000x. plz helpp