Page 41 - DMTH201_Basic Mathematics-1

Basic Mathematics – I

Notes
cot x =
–1

(iii) sec x =
–1
x = sec

= cos or =

–1
sec x =

Property 3
(i) sin (–x) = –sin x
–1
–1
–1
–1
(ii) tan (–x) = –tan x
(iii) cos (–x) = –cos x
–1
–1
Solution
–1
(i) Let sin (–x) =
–x = sin or x = –sin = sin(– )
–q = sin x or q = –sin x
–1
–1
–1
or sin (–x) = –sin x
–1
–1
(ii) Let tan (–x) =
–x = tan or x = –tan = tan (– )
–1
–1
q = –tan x or tan (–x) = –tan x
–1
–1
(iii) Let cos (–x) =
–x = cos or x = –cos = cos ( – )
–1
cos x = –
–1
–1
cos (–x) = – cos x
Property 4

(i) sin x + cos x =
–1
–1
–1
(ii) tan x + cot x =
–1

–1
–1
(iii) cosec x + sec x =
Solution

–1
–1
(i) sin x + cos x =

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