How do I use a graphing calculator to solve #-3cost=1#.? Thank you in advance :)

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1 Answer
Sep 29, 2017

#t~~1.91# or #t~~4.37#

Explanation:

I don't have a graphing calculator, but using the socratic Graph operation, I was able to plot the curve for #color(blue)(y=-3cos(x)#;
(note I had to substitute the variable #x# for the given variable #t#, but this should have no effect).

I've added the line for #color(green)(y=1)# which did not appear with the Graph operation to show where #color(blue)(-3cos(x))=color(green)1#

The Graph operation lets me point at points on the graph and displays the coordinates of that point (I assume your graphing calculator would allow something similar). These points will not be exact (depending on my inaccuracies in "pointing")

The #(x,y)# coordinates I got were #(1.9106,1.0)# and #(4.37255,1.0)#
(Remember that my #x# is #t# in the original question.