What is the exact value of Cos(240°-0°)?

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Answer 1 · 2018-02-25T03:52:43

#-0.5#

Given: #cos(240^@-0^@)#

#=cos(240^@)#

#=-1/2#

#=-0.5#

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Answer 2 · 2018-02-25T08:22:31

#-0.5#

# cos(240°-0°)#

#->cos(240°)#

#->cos(180° +60°)#

We know , #cos(180°+x) = -cosx#

So , #cos(180° +60°)#

#=-cos60°#

Also , #cos60°= 1/2#

So , #=-cos60°#

#= -1/2#

#= -0.5#