Answer:
[tex]\tan \left(2\theta\right)-1+\tan ^2\left(\theta\right)[/tex]
Key:
• [tex]-\left(a-b\right)=-a+b[/tex]
Step-by-step explanation:
[tex]\tan \left(2\theta\right)-\left(1-\tan ^2\left(\theta\right)\right)[/tex]
[tex]-\left(1-\tan ^2\left(\theta\right)\right)=-1+\tan ^2\left(\theta\right)[/tex]
[tex]=\tan \left(2\theta\right)-1+\tan ^2\left(\theta\right)[/tex]
