If `sin theta=0.7, "then" cos theta, 0 le theta lt 90^(@)` is
यदि `sin theta=0.7,` तो `cos theta, 0 le theta lt 90^(@)` है :

Options

A. `sqrt(0.51)`
B. `sqrt(9)`
C. `0.3`
D. `sqrt(0.49)`

Explanation

To find the value of \( \cos \theta \) given that \( \sin \theta = 0.7 \) and \( 0 \leq \theta < 90^\circ \), we can use the Pythagorean identity:

\[ \cos^2 \theta + \sin^2 \theta = 1 \]

### Step-by-Step Solution:

1. **Use the Pythagorean Identity**:
\[ \cos^2 \theta = 1 - \sin^2 \theta \]

2. **Substitute the value of \( \sin \theta \)**:
Since \( \sin \theta = 0.7 \), we substitute this into the equation:
\[ \cos^2 \theta = 1 - (0.7)^2 \]

3. **Calculate \( (0.7)^2 \)**:
\[ (0.7)^2 = 0.49 \]

4. **Subtract from 1**:
\[ \cos^2 \theta = 1 - 0.49 = 0.51 \]

5. **Take the square root**:
\[ \cos \theta = \sqrt{0.51} \]

6. **Determine the sign**:
Since \( 0 \leq \theta < 90^\circ \), \( \cos \theta \) must be positive. Thus:
\[ \cos \theta = \sqrt{0.51} \]

### Final Answer:
\[ \cos \theta = \sqrt{0.51} \]