Page 61 - Math Grade 12 (Advance)

PROEUS DARA

- t\5nni1Lf'ilti : ~tab wi1Lffllitsim~·u ro, nl li~th~nm'!5tHrnb~g~n o tfiQlS
1
Lmmsim~u [-n, n] '1

rh m gLmu ~s ~mr:lJb t9Jn tfiQlS tm ru~ R rnLmu cs ~15 [ -n, n] '1

0 I 0 Q &::~, I ':J ef
Wfmtftij2: WRJ1HtG~.fflr:1SbtubL1ll'tHSlHjfi'l5S y = f(x) = 2cosx-cos2x '1
Gtf'Jtv :
IN
" 0 •
" tL::l Snruln D = IR
"'
" ~15 : H9fi'l5S y = cosx 'i::!lS~ti P 1 = 2n , y = cos2x 'i::!lS~.u P = n '1
2

= 2cosx- cos2x = f(x)

tL:J1t~ y'= -2sinx+2sin2x = -2sinx+4sinxcosx = 2sinx(-1+2cosx)

y' = 0 hl'!5'!5b15 2sinx(- 1 + 2cosx) = 0
u
!U'\5'!5 rn sinx = 0 ' - 1 + 2 cosx = 0
u
o o:;:: "' o:;:: 1t
mmg sinx=O Sl~x=O, x=n Sb-1+2cosx=O Sl~x= 3 '1

- !i5 ffi1 t L:J1 t 1
!JJ
0
mmg O<x<n tfiQlS sinx>O '1 L::ltHS8 y' 'i::f1S!Uffi1L::l13 -1+2cosx
u E:g u
1 1t
- 1 + 2cosx > 0 cosx> U. 0<x<
2 3
1
-1 +2cosx<0 cosx < 2 't5 ~<x<rr
"'- 3

I 1t
X I 0 3
y'l 0 + b
I

HSfi'l5S f 'i::!lSHfim'i::!l t(~) = 2cos~- cos2~ = ? .l_ (-l) = ~ '1
1 3 3 3-2 2 2
'i::!lSHtiJli~'i::!l f(O) = 2cos0-cos2(0) = 1 Sb f(n) = 2cosn-cos2rt = -3

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