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If sec((pi)/(2)-alpha)+cosec((pi)/(2)-alpha). |
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Answer» Solution :`sec((pi)/(2)-alpha)+COSEC((pi)/(2)-alpha)` `=cosecalpha+secalpha=(1)/(SINALPHA)+(1)/(COSALPHA)=(cosalpha+sinalpha)/(sinalphacosalpha)` `=(sinalpha+sinalpha)/(sinalphasinalpha)[:'sinalpha-cosalpha=0impliessinalphacosalpha]` Again, `sinalpha=cosalpha=sin(90^(@)-alpha)` `impliesalpha=90^(@)-alphaor,2alpha=90^(@)or,alpha=(90^(@))/(2)=45^(@)` `:.(sinalpha+sinalpha)/(sinalpha.sinalpha)=(2sinalpha)/(sin^(2)alpha)=(2)/(sinalpha)=(2)/(sin45^(@))=(2)/((1)/(sqrt2))=2sqrt2`. Hence `sec((pi)/(2)-alpha)+cosec((pi)/(2)-alpha)=2sqrt2`. |
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