Trigonometry: Product Identities (DTube)

In this video I go over the trig product identities and provide a simple proof for them. The identities I cover are listed below:

sin(x)cos(y) = 1/2 [sin(x+y) + sin(x-y)]
cos(x)cos(y) = 1/2[cos(x+y) + cos(x-y)]
sin(x)sin(y) = 1/2[cos(x-y) - cos(x+y)]

In proving the above identities I make use of the identities which I covered in my earlier video (see the related videos below), specifically the identities for sin(x+/-y) and cos(x+/-y).

Download the notes in my video: http://1drv.ms/1DZu6XH

View Video Notes on Steemit: https://steemit.com/mathematics/@mes/trigonometry-product-identities

Related Videos:

Trigonometry Identities: cos(x +/- y) = cos(x)cos(y) -/+ sin(x)sin(y) :

Trigonometry Identities: sin(x +/- y) = sin(x)cos(y) +/- cos(x)sin(y):

Trigonometry Identities: cos(2π + x), sin(2π + x), cos(π/2 -x), sin(π/2 -x):

Half Angle Trigonometry Identities:

SUBSCRIBE via EMAIL: https://mes.fm/subscribe

DONATE! ʕ •ᴥ•ʔ https://mes.fm/donate

Like, Subscribe, Favorite, and Comment Below!

Official Website: https://MES.fm
Steemit: https://steemit.com/@mes
Gab: https://gab.ai/matheasysolutions
Minds: https://minds.com/matheasysolutions
Twitter: https://twitter.com/MathEasySolns
Facebook: https://fb.com/MathEasySolutions
LinkedIn: https://mes.fm/linkedin
Pinterest: https://pinterest.com/MathEasySolns
Instagram: https://instagram.com/MathEasySolutions
Email me: [email protected]

Try our Free Calculators: https://mes.fm/calculators

BMI Calculator: https://bmicalculator.mes.fm
Grade Calculator: https://gradecalculator.mes.fm
Mortgage Calculator: https://mortgagecalculator.mes.fm
Percentage Calculator: https://percentagecalculator.mes.fm

Try our Free Online Tools: https://mes.fm/tools

iPhone and Android Apps: https://mes.fm/mobile-apps

▶️ DTube
▶️ IPFS