গুণফল ,ভাগফল ও সংযোজিত ফাংশনের অন্তরজ/Chain Rule

If the angle between the curves y=2x y = 2^x and y=3x y=3^x is α, \alpha, then the value of tanα \tan \alpha is equal to :

হানি নাটস

Given curves are y=2x y = 2^x and y=3x y =3^x

The point of intersection is 3x=2xx=0 3^x = 2^x \Rightarrow x = 0

On differentiating w.r.t. x,x, we get

dydx=2xlog2=m1 \dfrac {dy}{dx} = 2^x \log 2 = m_1

and dydx=3xlog3=m2 \dfrac {dy}{dx} = 3^x \log 3 = m_2

Therefore, tanα=m2m11+m1m2 \tan \alpha = \dfrac {m_2 - m_1}{1 + m_1m_2}

=3xlog32xlog21+3x×2xlog3×log2 = \dfrac {3^x \log 3 - 2^x \log 2 }{1+3^x \times 2^x \log 3 \times \log 2}

At x=0x=0,

tanα=30log320log21+30×20log2log3\tan \alpha = \dfrac {3^0 \log 3 - 2^0 \log 2 }{1 + 3^0 \times 2^0 \log 2 \log 3 }

=log321+log2log3 = \dfrac { \log \dfrac {3}{2} } { 1 + \log 2 \log 3 }

গুণফল ,ভাগফল ও সংযোজিত ফাংশনের অন্তরজ/Chain Rule টপিকের ওপরে পরীক্ষা দাও