preCal graphs of trig: y-int. of y = cos(x), soln to cos(x)

[zman0825]

Find the y-intercept of the graph of y = cos x.

For what values of x is the graph of y = sin x increasing from 0 to 1, when -? ? x ? ??

For what values of x does cos x = 0, when 0 ? x ? 2??

I dont really know where to begin with any of these..........so what do i do?

 

[Deleted member 4993]

Re: preCal graphs of trig

Find the y-intercept of the graph of y = cos x.



For what values of x is the graph of y = sin x increasing from 0 to 1, when -? ? x ? ??


For what values of x does cos x = 0, when 0 ? x ? 2??



I dont really know where to begin with any of these..........so what do i do? - Read your textbook

First thing you do is to get a graphing calculator and graph these graphs.

For graph #1 - where does the graph intersect the y-axis ( i.e. what is cos(0))?

Tell us what do you find.

 

[fasteddie65]

Find the y-intercept of the graph of y = cos x.
To find the y-intercept, let x = 0. y = cos 0 = 1. The y-intercept is (0, 1).

For what values of x is the graph of y = sin x increasing from 0 to 1, when -? ? x ? ??
sin 0 = 0 and sin (?/2) = 1, so the graph is increasing on [0, ?/2]. Also sin (-2?) = 0 and sin (-3?/2) = 0, so the graph is increasing on [-2?, -3?/2] also.

For what values of x does cos x = 0, when 0 ? x ? 2??
cos (?/2) = 0 and cos (3?/2) = 0.