Respuesta :

Answer:

csc(-112°)=-csc(68°)

Step-by-step explanation:

Since cosec(x) and sin(x) are reciprocals of each other,

cosec(-112°)=[tex]\frac{1}{sin(-112^{\circ})}[/tex]

                  =[tex]\frac{1}{-sin(112^{\circ})}[/tex]

                 =[tex]\frac{1}{-sin(180^{\circ}-68^{\circ})}[/tex]     (since 112=180-68)

                 =[tex]\frac{1}{-sin(68^{\circ})}[/tex]              (since sin(180-x)=sinx)

                 =[tex]\frac{-1}{sin(68^{\circ})}[/tex]               (since [tex]\frac{a}{-b}= \frac{-a}{b}[/tex])

                 =-cosec(68°)

Answer:

Step-by-step explanation:

To find: [tex]\csc \left ( -112^{\circ} \right )[/tex]

Solution:

Trigonometric expression is an expression consisting of trigonometric ratios like [tex]\sin ,\tan ,\cos ,\csc ,\cot ,\sec[/tex]

Trigonometric ratios refers to the relation between the sides of right angled triangle and it's angles.

We know that angle [tex]-112^{\circ}[/tex] lies in the fourth quadrant in which [tex]\csc[/tex] is negative

So, [tex]\csc \left ( -112^{\circ} \right )=-\csc \left ( 112^{\circ} \right )[/tex]

We can write [tex]-\csc \left ( 112^{\circ} \right )=-\csc \left ( 180^{\circ}-68^{\circ} \right )[/tex]

We know that angle [tex]180^{\circ}-68^{\circ}=112^{\circ}[/tex] lies in second quadrant in which [tex]\csc[/tex] is positive

[tex]-\csc \left ( 180^{\circ}-68^{\circ} \right )=-\csc68^{\circ}[/tex]

Therefore, we get

[tex]\csc(-112^{\circ})=-\csc(112^{\circ})=-\csc \left ( 180^{\circ}-68^{\circ} \right )=-\csc68^{\circ}[/tex]