Lesson#7
Question No. 5
Q5: If α,β,γ are the angles of a triangle ABC, then prove that;
(i): sin(α+β)=sinγ|Solution:
Sum of three angles in a triangle is 180°|α+β+γ=180 ⇒α+β=180°−γ|sin(α+β)=sin (180° −γ)|sin(α+β)=sin γ (Proved)
Math.Ex.10.1, Part7(10.1),
(iii): cos(α+β)=− sinγ
(iv): tan(α+β)+tanγ" " =0
(ii): cos((α+β)/2)=sin γ" " /2
This is the end of Ex. 10.1, now practice yourself.
Thanks.
Trigonometric Identities
Chapter No 10
Exercise No 10.1
Mathematics
part 1
Question No. 5
Q5: If α,β,γ are the angles of a triangle ABC, then prove that;
(i): sin(α+β)=sinγ|Solution:
Sum of three angles in a triangle is 180°|α+β+γ=180 ⇒α+β=180°−γ|sin(α+β)=sin (180° −γ)|sin(α+β)=sin γ (Proved)
Math.Ex.10.1, Part7(10.1),
(iii): cos(α+β)=− sinγ
(iv): tan(α+β)+tanγ" " =0
(ii): cos((α+β)/2)=sin γ" " /2
This is the end of Ex. 10.1, now practice yourself.
Thanks.
Trigonometric Identities
Chapter No 10
Exercise No 10.1
Mathematics
part 1
Category
📚
Learning