Answer: The required simplified value of the given expression is 2.
Step-by-step explanation: We are given to simplify the following trigonometric expression :
![T_E=(\sin\theta-\cos\theta)^2+(\sin\theta+\cos\theta)^2~~~~~~~~~~~~~~~~~~~~~~~~~(i)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/p4ccclzrlm8wfh6u3sdna7uvee1nmiq6fs.png)
We will be using the following formulas :
![(i)~(a-b)^2=a^2-2ab+b^2,\\\\(ii)~(a+b)^2=a^2+2ab+b^2,\\\\(iii)~\sin^2\theta+\cos^2\theta=1.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/r3owdszsd2onacp9ti6zm6tp1moxdcuh31.png)
From (i), we have
![T_E\\\\=(\sin\theta-\cos\theta)^2+(\sin\theta+\cos\theta)^2\\\\=\sin^2\theta-2\sin\theta\cos\theta+\cos^2\theta+\sin^2\theta+2\sin\theta\cos\theta+\cos^2\theta\\\\=2(\sin^2\theta+\cos^2\theta)\\\\=2*1\\\\=2.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/a703i5426ay1quonfg59ktn7v7tf98twsp.png)
Thus, the required simplified value of the given expression is 2.