Question : The value of expression $4\left(\sin ^6 A+\cos ^6 A\right)-6\left(\sin ^4 A+\cos ^4 A\right)+8$ is:
Option 1: 4
Option 2: 8
Option 3: 7
Option 4: 6
Recommended: How to crack SSC CHSL | SSC CHSL exam guide
Don't Miss: Month-wise Current Affairs | Upcoming government exams
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 6
Solution : We know that $\left(\sin ^6 \theta+\cos ^6 \theta\right)=(\sin^2 \theta +\cos^2 \theta)(\sin^4 \theta + \cos^4 \theta-\sin^2 \theta\cos^2 \theta)$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)=4(1)(\sin^4 \theta + \cos^4 \theta-\sin^2 \theta\cos^2 \theta)$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)-6\left(\sin ^4 A+\cos ^4 A\right)=4(\sin^4 \theta + \cos^4 \theta)-4\sin^2 \theta\cos^2 \theta)-6\left(\sin ^4 A+\cos ^4 A\right)$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)-6\left(\sin ^4 A+\cos ^4 A\right)=-2(\sin^4 \theta + \cos^4 \theta+2\sin^2 \theta\cos^2 \theta)$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)-6\left(\sin ^4 A+\cos ^4 A\right)=-2(\sin^2 \theta +\cos^2 \theta)^2$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)-6\left(\sin ^4 A+\cos ^4 A\right)+8=-2(1)^2+8$ $⇒4\left(\sin ^6 \theta+\cos ^6 \theta\right)-6\left(\sin ^4 A+\cos ^4 A\right)+8=6$ Hence, the correct answer is 6.
Candidates can download this e-book to give a boost to thier preparation.
Application | Eligibility | Admit Card | Answer Key | Preparation Tips | Result | Cutoff
Question : If $\sin A+\sin ^2 A=1$, then the value of the expression $\left(\cos ^2 A+\cos ^4 A\right)$ is
Option 1: $\frac{3}{2}$
Option 2: $1$
Option 3: $2$
Option 4: $\frac{1}{2}$
Question : What is the value of $\frac{\sin \theta+\cos \theta}{\sin \theta-\cos \theta}+\frac{\sin \theta-\cos \theta}{\sin \theta+\cos \theta}$?
Option 1: $\frac{1}{\left(\sin ^2 \theta-\cos ^2 \theta\right)}$
Option 2: $2\left(\sin ^2 \theta-\cos ^2 \theta\right)$
Option 3: $\frac{2}{\left(\sin ^2 \theta-\cos ^2 \theta\right)}$
Option 4: $\sin ^2 \theta-\cos ^2 \theta$
Question : If $\sin \theta \cos \theta=\frac{\sqrt{2}}{3}$,then the value of $\left(\sin ^6 \theta+\cos ^6 \theta\right)$ is:
Option 1: $\frac{1}{3}$
Option 2: $\frac{4}{3}$
Option 3: $\frac{2}{3}$
Option 4: $\frac{5}{3}$
Question : Simplify the given expression $\frac{3\left(\sin ^4 z-\cos ^4 z+1\right)}{\sin ^2 z}$
Option 1: 9
Option 2: 2
Option 3: 4
Question : If $\left (a+b \right):\left (b+c \right):\left (c+a \right)= 6:7:8$ and $\left (a+b+c \right) = 14,$ then value of $c$ is:
Option 1: 6
Option 2: 7
Option 3: 8
Option 4: 14
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile