Question

The value of (sin 7x + sin 5x) /(cos 7x + cos 5x) + (sin 9x + sin 3x) / (cos 9x + cos 3x) is

Answer 1

Answer:

LHS = [(sin7x + sin5x) + (sin9x + sin3x)] [(cos7x + cos5x) + (cos9x + cos3x)]

use the formula,

sinC + sinD = 2sin(C+D)/2.cos(C-D)/2 cosC + cosB = 2cos(C+D)/2.cos(C-D)/2

= {2sin6x.cosx +2sin6x.cos3x}/ {2cos6x.cosx + 2cos6x.cos3x}

- 2sin(x(cosx + cos3x)/ 2cos6x(cosx+cos3x)

= sin6x/cos6x

= tan6x = RHS

hence proved

if found helpful mark it as brainiliest and follow plz

Answer 2

Answer:

An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. ... Ecosystems can be very large or very small.