(cot2a.tana) / tan²-1=? (-1/2)

sin²(a-3∏/2).(1-tan²a).tan(∏/4+a) / cos²(∏ /2 -a)=? (cosec²a +2cota)

(cosma-cosna) / (sinna-sinma)=? tan(m+n/2 a)

sin⁴∏/8 + cos⁴∏/8=? (3/4)

(4cosx/3) .(cos∏+x /3) .(cos∏-x /3)=? (cosx)

nolur yardım edin:(:(

1)(1/tan2a).tana/(tan²-1)

[(1-tan²a)/(2.tana)] . tana /(tan²-1)=-1/2


2)cos²a . (1-tan²a) . (1+tana)/(1-tana) . 1/sin²a

(1+tana)²/tan²a =[(1+tana)/tana]² = (cota+1)²=cot²+2cota+1=2cota+(1/sin²a)


3)
x=(m+n)a/2
y=(m-n)a/2 olsun

[cos(x+y)-cos(x-y)]/[sin(-y+x)-sin(-y-x)] =[-2.sinx.siny]/[2.(sin-y) .cosx] =tanx


4)2cos²pi/8 =1+cospi/4 ise cos²pi/8 =(2+√2)/4 bulunur

=[sin²pi/8]²+[cos²pi/8]²
=[(1-cos²pi/8)]²+[cos²pi/8]²
=[(2-√2)/4]²+[(2+√2)/4]²
=12/16=3/4

çok teşekkür ederim çok sağol