Question

Cos 48 sin 18 -sin48 cos 18=-1/2

Answer 1

Step-by-step explanation:

sin18cos48 - sin 48cos18

we know

sin( A-B) = sinAcosB - sinBcosA

sin(48-18) = sin48cos18 - sin18cos48

sin30 = sin48cos18 - sin18cos48

sin48cos18 - sin18cos48 = 1/2

taking - as common

-(sin18cos1/48 - sin48cos18) =1/2

sin18cos1/48 - sin48cos18 = -1/2

this will clarify you☺️

pls follow me I am new here..

Answer 2

Answer:

hence proved

therefore, cos48sin18 -sin48 cos18=-1/2

Step-by-step explanation:

let us rewrite

let us rewrite cosAsinB -sinAcosB

let us rewrite cosAsinB -sinAcosBinto

• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB
• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB-(sinAcosB - cosAsinB)
• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB-(sinAcosB - cosAsinB)- [sin(A -B)]
• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB-(sinAcosB - cosAsinB)- [sin(A -B)]- [sin(48-18)]
• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB-(sinAcosB - cosAsinB)- [sin(A -B)]- [sin(48-18)]- sin30
• let us rewrite cosAsinB -sinAcosBinto - sin AcosB + cosA sinB-(sinAcosB - cosAsinB)- [sin(A -B)]- [sin(48-18)]- sin30-1/2