1. Simplify the following expression:

[tex]\[ \frac{\cos 40^{\circ} - \sin 30^{\circ}}{\sin 60^{\circ} - \cos 50^{\circ}} = \tan 50^{\circ} \][/tex]



Answer :

Let's solve the equation [tex]\(\frac{\cos 40^{\circ} - \sin 30^{\circ}}{\sin 60^{\circ} - \cos 50^{\circ}} = \tan 50^{\circ}\)[/tex] step-by-step.

1. Calculate each trigonometric function value:

[tex]\[ \cos 40^{\circ} \approx 0.766 \][/tex]

[tex]\[ \sin 30^{\circ} = 0.5 \][/tex]

[tex]\[ \sin 60^{\circ} \approx 0.866 \][/tex]

[tex]\[ \cos 50^{\circ} \approx 0.643 \][/tex]

[tex]\[ \tan 50^{\circ} \approx 1.192 \][/tex]

2. Calculate the numerator:

[tex]\[ \cos 40^{\circ} - \sin 30^{\circ} \approx 0.766 - 0.5 = 0.266 \][/tex]

3. Calculate the denominator:

[tex]\[ \sin 60^{\circ} - \cos 50^{\circ} \approx 0.866 - 0.643 = 0.223 \][/tex]

4. Calculate the quotient (left-hand side of the equation):

[tex]\[ \frac{\cos 40^{\circ} - \sin 30^{\circ}}{\sin 60^{\circ} - \cos 50^{\circ}} \approx \frac{0.266}{0.223} \approx 1.192 \][/tex]

5. Compare with [tex]\(\tan 50^{\circ}\)[/tex]:

[tex]\[ \tan 50^{\circ} \approx 1.192 \][/tex]

6. Conclusion:

The left-hand side of the equation [tex]\(\frac{\cos 40^{\circ} - \sin 30^{\circ}}{\sin 60^{\circ} - \cos 50^{\circ}}\)[/tex] is equal to the right-hand side [tex]\(\tan 50^{\circ}\)[/tex]. This confirms the given equation.

Thus,

[tex]\[ \frac{\cos 40^{\circ} - \sin 30^{\circ}}{\sin 60^{\circ} - \cos 50^{\circ}} = \tan 50^{\circ} \][/tex]

is not true because in this case, although [tex]\(\frac{\cos 40^\circ - \sin 30^\circ}{\sin 60^\circ - \cos 50^\circ}\)[/tex] gives a result that numerically matches [tex]\(\tan 50^\circ\)[/tex], with the exact precision we can see that it does not equal to [tex]\(\tan 50^\circ\)[/tex].