The value of \(\frac{{\left[ {4co{s^4}32^\circ cose{c^2}58^\circ – sin63^\circ cos27^\circ – co{s^2}63^\circ \; + \;1} \right]}}{{\left[ { – cose{c^2}24^\circ \; + \;ta{n^2}66^\circ – se{c^2}31^\circ \; + \;co{t^2}59^\circ } \right]{{\cos }^2}32}}\) is –
1. 1
2. -1
3. 2
4. -2
1. 1
2. -1
3. 2
4. -2
Correct Answer – Option 4 : -2
GIVEN:
\(\frac{{\left[ {4co{s^4}32^\circ cose{c^2}58^\circ – sin63^\circ cos27^\circ – co{s^2}63^\circ \; + \;1} \right]}}{{\left[ { – cose{c^2}24^\circ \; + \;ta{n^2}66^\circ – se{c^2}31^\circ \; + \;co{t^2}59^\circ } \right]{{\cos }^2}32^\circ }}\)
FORMULA USED:
sin(90° – x) = cos x, cosec(90° – x) = sec x
(1 – sin2x) = cos2x
(1 – cos2x) = sin2x
CALCULATION:
\(\frac{{\left[ {4co{s^4}32^\circ cose{c^2}58^\circ – sin63^\circ cos27^\circ – co{s^2}63^\circ \; + \;1} \right]}}{{\left[ { – cose{c^2}24^\circ \; + \;ta{n^2}66^\circ – se{c^2}31^\circ \; + \;co{t^2}59^\circ } \right]\;{{\cos }^2}32^\circ }}\)
= \(\frac{{\left[ {4co{s^4}32^\circ se{c^2}32^\circ – sin63^\circ sin63^\circ – co{s^2}63^\circ \; + \;1} \right]}}{{\left[ { – se{c^2}66^\circ \; + \;ta{n^2}66^\circ – cose{c^2}59^\circ \; + \;co{t^2}59^\circ } \right]\;{{\cos }^2}32^\circ }}\)
= \(\frac{{\left[ {4co{s^2}32^\circ – {{\sin }^2}63^\circ – co{s^2}63^\circ \; + \;1} \right]}}{{\left[ { – se{c^2}66^\circ \; + \;ta{n^2}66^\circ – cose{c^2}59^\circ \; + \;co{t^2}59^\circ } \right]\;{{\cos }^2}32^\circ }}\)
= \(\frac{{\left[ {4co{s^2}32^\circ } \right]}}{{\left[ { – 1 – 1} \right]{{\cos }^2}32^\circ }}\)
= 4/(- 2)
= – 2