Question

ICSE Mathem
21.10
3. (sin 0+ cosec 0)2 + (cos e + sec 0)2 = 7 + tan2 + cot 2

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Answer 1

Step-by-step explanation:

(sin0+cosec0)2+(cos0+sec0)2=7+tan2+cot2

=(1/cosec0+cosec0)2+(1/sec0+sec0)2

=1/cosec2+cosec20+2*1/cosec0*cosec0+1/sec20+sec2+2*1/sec0*sec0

=sin20+cosec20+2+cos20+sec20+2

=sin20+cos20+1+tan20+1+cot20+4 (using

identities given in NCERT)

=1+2+4+tan20+cot20

=7+tan20+cot20

hence proved