Neha
Last Activity: 6 Years ago
According to the question
5tan theta =4
Then,tan theta =4/5
Draw a triangle ABC ∆,90^°at angle B&angleC is theta, such that side AB is the perpendicular,BC the base &AC be the hypotenuse
Then we know ,tan theta=perpendicular/base=AB/BC
Now let AB=4k&BC=5k
In ∆ABC
AC²= AB² + BC²
AC²=4k²+5k²
AC²=16k²+25k²
AC=√41k
Sin theta=perpendicular/hypotenuse=4k/√41k=4/√41
Cos theta = base/perpendicular=5k/√41k=5/√41
5sin theta-3cos theta/5sin theta-2cos theta
5×4/√41-3×5/√41/5×4/√41+2×5√41
=5/√41×√41/30
=1/6