Jika tan a=0,75 dengan a sudut lancip maka nilai cosec 2a=

tan a = 0,75 = 3/4
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3² + 4² = 25
           = 5²
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maka 
sin a = 3/5
cos a = 4/5

1/cosec2a
= 1/sin2a
= 1/(2 sin a . cos a)
= 1/(2 (3/5) . (4/5))
= 1/(24/25)
= 25/24