cos 2φ/ sin 3φ < 0, if φ lies in:
(a) {(13Ï€/48),(14Ï€/48)}
(b) {(14Ï€/48),(18Ï€/48)}
(c) {(18Ï€/48),(23Ï€/48)}
(d) {(Ï€/2),Ï€}
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3 Answers
Lokesh Verma
·2009-11-17 22:17:42
Hint: Draw the graph.. of cos 2φ and sin 3φ individually..
or else think of it like cos 2φ x sin 3φ < 0
because you are multiplying by sin2 3φ
Can you pull this off now?