Math, asked by danaboina2021, 30 days ago

find the value of cos(25°)cos(20°)-sin(25°)sin (20°)​

Answers

Answered by srps915
0

Answer:

cos=5degree

Step-by-step explanation:

Formula used:

cosα cosβ+sinα sinβ=cos(α−β)

cos25

cos20

+sin25

sin20

=cos(25

−20

)=cos5

have a good day

Answered by Anonymous
3

  \bf\bigstar  \:  Given : -

  • cos(25°)cos(20°)-sin(25°)sin (20°)

 \bf \bigstar \: To \:  Find :-

  • Their value

 \bf  \bigstar \: Solution :-

We know that,

 \boxed{ \sf \: cos( \alpha)cos( \beta) - sin( \theta)sin( \beta) = cos( \alpha  - \beta)}

Therefore,

  \sf\implies \:cos(25 ^\circ)cos(20^\circ)-sin(25^\circ)sin (20^\circ) \\  \\  \sf \implies \: cos(25^\circ - 20^\circ) \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \\  \\  \sf \implies \: cos \: 5^\circ \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:  \:

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