just find
5cos 70°
how can we calculwte the value of
Cot 70 degree+4 cos 70 degree
3 answers
oops, read the first as cos
I would just use my calculator
I would just use my calculator
L.H.S= cos 70/sin 70+4 cos 70
= cos 70+4 cos 70 sin 70/sin 70
=cos 70+2 sin 40/sin 70
= cos 70+2 cos 50/sin 70
= cos 70+cos 50+cos 50/sin 70
= 2 cos 60 cos 10+cos 50/sin 70
= cos 10+cos 50/sin 70
= 2 cos 30 cos 20 /cos 20
= root 3
= cos 70+4 cos 70 sin 70/sin 70
=cos 70+2 sin 40/sin 70
= cos 70+2 cos 50/sin 70
= cos 70+cos 50+cos 50/sin 70
= 2 cos 60 cos 10+cos 50/sin 70
= cos 10+cos 50/sin 70
= 2 cos 30 cos 20 /cos 20
= root 3
1 answer